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Firebug causes Firefox to be unresponsive

I'm a beginner web developer. I often use Firebug to debug my JavaScript.
Problem is that there are some script files from my page's UI that have a lot of code and this causes my web browser to be unresponsive, i.e. I get a dialog saying the script is unresponsive. Basically this happens when I am within Firebug's Script panel.
How can I deal with this?

I tried finding solution to this problem and nothing.
As for the answer I think the best was posted by #Pablo(can't assign answer to comment unfortunately) and it is simply trying out Google Chrome console. None of the problems I mentioned exists here.
Cheers guys!

I have had the same problem debugging some of our older scripts that make extensive use of the eval() function.
This causes many scripts to be displayed within the Script Location Menu. (Each dynamically generated script is represented there.)
A possible solution, given that it was caused by the number of files in my instance, might be to see if you can bypass the problem entirely by utilizing fewer source files for the same code. Using a 'built' version of whatever frameworks you use might alleviate the problem. (Particularly if they still are debug-able in a built form.)
If that does not work, you might try debugging using Firefox' built-in debugger (available via Ctrl+Shift+S. (Or switch to another browser to do the debugging, but that is obviously a far less desirable solution.)

Windows Gadgets: Testing environment?

Is there anything that provides a console, error logging, etc. for testing Windows Gadgets? I've searched but I'm unable to find anything.
Thanks in advance!

A simple and easy start is to just use any web developing toolkit. I found out myself that for developing simple Windows Gadgets, Notepad++ and Firefox with its Web Developer toolbar was more than enough. You can implement all the business logic and just test the results in a browser. Actually starting it as a Gadget was only needed to fine-tune some graphical glitches that always occur because of different browsers still interpreting CSS a little differently.
Firefox has some nice tools for debugging Javascript.

You can use firebug lite for IE (i.e put a script tag and include the latest firebug lite version).It does look a bit crude but it works nonetheless and its seamless integration for testing.
http://getfirebug.com/lite/ie.html
Though your gadget might seem a bit mutilated when using it.
:)

Profiling JavaScript without crashing your browser

So tried my hand at profiling some code and I figured the easiest way to do it (at least on Firefox) was to use either console's time/timeEnd or profile/profileEnd, and I tried both.
The problem I have is with the number of runs I can do before Firefox crashes on me. Now I won't paste the code here because it's typical benchmarking code (and it's very messy), but obviously the gist of it is that it runs functions (a test is represented with a function), logging their execution time for a certain number of runs.
Now with for example, 5e4 it sorta works but I don't think it's enough to spot (very) micro optimizations, but more than that, it crashes.
So how do you profile your JavaScript? Because this way, it's barely feasible.

When I used to profile my JavaScript code I used Chrome's profiler; the JavaScript Console in the developer view gives it, and it pretty much worked for me. Have you ever tried it?

I have tried profiling a page with a lot of scripting in Firebug on FF4 and the same in Chrome (last version). Firefox crashed within a second or two, Chrome didn't seem to have problems with it. Maybe you can find something on it in the Firebug issues list?

Although not a traditional code profiler, I recommend Google's Speed Tracer:
Using Speed Tracer you are able to get a better picture of where time is being spent in your application. This includes problems caused by JavaScript parsing and execution, layout, CSS style recalculation and selector matching, DOM event handling, network resource loading, timer fires, XMLHttpRequest callbacks, painting, and more.

I think the profiler in the JavaScript Debugger (aka Venkman) is quite good. The version currently on addons.mozilla.org is not compatible with Firefox 4, but the change necessary to make it work has been committed. See https://bugzilla.mozilla.org/show_bug.cgi?id=614557 for details.

dynaTrace AJAX edition(free)- one more tool in your bag. Offers a little bit more detailed performance metrics, IMHO. They used to have it only for IE, but their new one supports FF too. Also see Steve Sounder's blog

debugging javascript for IE6

firebug is quite useful tool that I can't think myself living without it. I also downloaded the js file that helps you get similar functionality when using IE6 hoping it would help me resolve some issues, however, the messages I receive are not quite friendly such as:
"Expected ':' (default2.aspx,16)" - on line 16 there is nothing that can possibly expect a ":"
or
"Object doesn't support this property or method (default2.aspx,198)" on line 198 nothing interesting that can require any support for anything.
my site looks like a different web site in IE6.. most of the css doesnt work, some of the jquery functions doesnt work and I need to get this site work in IE6. Any help would be appreciated in terms of;
how to know what the messages (like the ones above) mean in IE6 and how to effectively debug js in IE6?
where to start for css compatibility.. e.g. shall I create different css files for different browsers and load them by detecting the browser? or are there any common issues and hacks?
I am lost so please give me any direction to start..

You debug javascript in IE6 with:-
Microsoft Script Debugger
The QuirksMode website is useful site to determine which bits of CSS is implemented in what way by which browser. Note IE6 "standards" mode rendering is notoriously buggy.

You can try Companion JS. It is pretty good with respect to debugging. It requires Microsoft Script Debugger as well.
Companion JS thankfully supports "console.log" (via firebug). It is free tool. Debug-bar is a good CSS-DOM-Javascript debugger, but it is not free for commercial purposes.

The two tools I use are:
Web Development Helper
IE Developer Toolbar
They somewhat duplicate each other's functionality, but each one can be useful for different tasks. The Web Development Helper has a built in JavaScript console, it's not as good as Firebug but it's better than nothing and easier than the MS Script Debugger.

"Expected ':' (default2.aspx,16)" - on line 16 there is nothing that can possibly expect a ":"
The error won't be on line 16 of your .aspx file, probably not even on line 16 of the HTML source the aspx file produces. It'll be near line 16 of one of your linked .js files. Which one? IE won't tell you.
You could find out by adding extra lines at the start of each .js file and seeing what happens to the error line number, but it's probably better just to install Script Debugger already.
IE8 finally fixes this.
shall I create different css files for different browsers and load them by detecting the browser? or are there any common issues and hacks?
Start with standards-compliant CSS, and a Standards Mode doctype, and test in Firefox 3, or Opera, Safari, Chrome. Mostly they'll give you more or less the same results. Now test in IE7 and hopefully it'll just work.
The troublesome browser today is IE6. You may well need to add hacks for it. You can do this in a separate stylesheet if there's a lot of them, or just use the "* html" hack for the occasional rule.
All the older hacks, your Box Model Hacks and so on, you can forget about. They're only of use for IE5, which is dead, and IE6 Quirks Mode, which you shouldn't be using.

or have an AJAX call to send debug variables/messages to ASP (PHP) script that will log it. this will help if the problem is with variables undefined or having similar issues.

For what it's worth, I've found the line number errors are much more accurate when using a separate js file.
I still use IE6 as my primary browser when developing. It saves a lot of headaches later, since you will often find CSS issues much earlier in the process.
I also find it helpful to use a JavaScript logger to send debug messages. This being an alternative to a bunch of alert messages. Personally, I use the yahoo UI logger

I use one of two things for js debugging: Microsoft Script Editor or Firebug Lite. Go here for more info.
As for the CSS, I recommend a CSS Reset. And for the little differences in IE6, consider using conditional comments.
When making an an application to be used in multiple browsers, quirksmode is a lifesaver.
EDIT: blackbird is a nice cross-browser tool for tracking state.

I've used MS Script Debugger with some success, also IE Developer Toolbar and Firebug Lite. I recently learned about MS Visual Web Developer Express Edition, which has been a big improvement so far.

How to suppress javascript errors for sites I'm not developing?

I like to keep javascript debugging enabled in my browser so when I'm developing my own code I can instantly see when I've made an error.
Of course this means I see errors on apple.com, microsoft.com, stackoverflow.com, cnn.com, facebook.com. Its quite fun sometimes to see just how much awful code there is out there being run by major sites but sometimes it gets really annoyed.
I've wondered for YEARS how to change this but never really got around to it. Its particularly annoying today and I'd really like to know of any solutions.
The only solution I have is : use a different browser for everyday browsing.
I'm hopin theres some quick and easy plugin someone can direct me to where I can toggle it on and off based upon the domain i'm on.
Edit: I generally use IE7 for everyday browsing

Firebug lets you enable/disable debugging for different domains.

Script Debugging in IE7 is controlled by a registry key. (An addon could probably toggle it. I just don't know of any.)
So, how I handle this is to write a registry script to turn it on or off. Then, I put a link to those scripts on my windows quick-launch bar and change their icons to be more appropriate. Then, I can just click one of the links to turn on or off IE script debugging.
Turn Off:
REGEDIT4
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main]
"Disable Script Debugger"="yes"
"DisableScriptDebuggerIE"="yes"
Turn ON:
REGEDIT4
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main]
"Disable Script Debugger"="no"
"DisableScriptDebuggerIE"="no"

Firefox lets you use different profiles. Each profile can have separate preferences, themes and plugins. Start firefox on Windows this way: firefox.exe -ProfileManager to create or manage profiles.
I use Firefox and Webkit for web debugging and Safari for regular web browsing, however. Firefox is just better for web development, and I prefer Safari overall.

I keep those annoying popups on for Internet Explorer, and you're right. It's amazing how few developers ever bother testing their code in IE. As a web developer, it's sorta your duty, right? Seeing as how it still accounts for like 60% of traffic to most sites.
Anyway, in answer to your question, I simply switched to Chrome for everyday browsing, and only use IE for testing and developing.

You have two options.
Change and use a browser that allows you to have site specific configuration (check out Firefox with Firebug), or
Use different browsers for developing and everyday use.

CompanionJS doesn't let you toggle debugging on a domain basis, but makes the error messages less obtrusive for casual surfing, and makes script debugging in general more user friendly.

Chrome doesnt bug you unless you first open the javascript debugger window

If you want to test and debug JavaScript, Firefox and Firebug are unrivalled in terms of features and ease of use. Chrome is not as powerful as Firebug, no matter what anyone else tells you.