Are you or your test team missing JavaScript errors while testing Web applications? Now days, the errors aren't so in your face like they used to be. You have to know where to look for them. If I had a quarter for every time I had to ask a tester who was testing browser compatibility on Netscape or FireFox "Where's your JavaScript console?" I'd have....well at least a few dollars. When the question was asked, sometimes the reply would be "How do I get to that"? Ouch...Uhm, yeah, could you retest that? Sometimes what I consider the basics I guess aren't so basic. I guess this is a perfect training opportunity for me. Here's how you do it my friends:

Internet Explorer 6
By default the popup window with script errors do not display in IE. In order to receive the actual error (when it occurs) you'll need to enable the following setting: Tools > Internet Options > Advanced > Browsing: Display a notification about every script error

With or without this option selected you'll always receive an error icon in the bottom-left of the browser window. Double clicking the error icon will display the error window. The icon can be easy to miss though. So IMHO you should enable the "Display a notification about every script error" setting to avoid missing errors.

FireFox 1.x and Netscape 8.x
Script errors are hidden. In order to see the errors you'll need to use the JavaScript console. This can be viewed two ways:
1. Type the text "JavaScript:" in the address bar and press enter.
2. Navigate to Tools > JavaScript Console

Netscape 4.x
Script errors are hidden. In order to see the errors you'll need to use the JavaScript console. This can be done by:
1. Type the text "JavaScript:" in the address bar and press enter.

Netscape 6.x
Script errors are hidden. In order to see the errors you'll need to use the JavaScript console. This can be viewed two ways
1. Type the text "JavaScript:" in the address bar and press enter.
2. Tasks > Tools > JavaScript Console

Netscape 7.x
Script errors are hidden. In order to see the errors you'll need to use the JavaScript console. This can be viewed two ways
1. Type the text "JavaScript:" in the address bar and press enter.
2. Tools > Web Development > JavaScript Console

Opera 8.x
Script errors are hidden. In order to see the errors you'll need to use the JavaScript console. This can be done by:
1. Tools > Advanced > JavaScript console

With Netscape, FireFox and Opera I advise you to leave the JavaScript console open at all times and in plain view so that when the event/error occurs you know what page you were on and what you were doing to cause the error. This can be painful when running at a small resolution because you end up trying to fit two windows into the display. It doesn't rank high on the usability or convenience charts, but how often is testing convenient?! Wouldn't that be a nice testing enhancement if they integrated the console INTO the browser window?

Get in the habit, keep that console open and find those JavaScript errors. No seriously, I'm sick of seeing them when I visit your site... ;)