Today in the Web 2.0 world you do alot of
JavaScript coding being DHTML, all the set of frameworks (jQuery etc) or do AJAX. The biggest thing that all JavaScript coders (even the pros) moan about isn't how difficult it is to test/debug JavaScript (tools like Firebug or JavaScript support in MS Visual Studio.Net 2008 IE make this very easy) but the dreadful word: "browser compatibility".... Yes Internet Explorer (IE) vs Firefox etc. All the things that make you want to scream / run away crying!
Its such a pain for me, since I use Google Chrome as my main default browser so everything just works but then later I found that it doesn't work in IE because of some browser compatibility issue or a weird way that IE handle some JavaScript.... The main problem here is that the browser companies (Microsoft, Mozilla etc) doesn't come together and work on a solid JavaScript standard. Ladies & gents, that is the reason why we've language standards!! There is a promise that the next version of JavaScript will be standard accross all browsers but thats only "promises".
For example:
var name = "Lennie";
alert(name[0]);
where you want the first characters e.g. "L" but in IE (IE is always the bad child it seams...) it returns "undefined" :-(
So you need to write it:
var name = "Lennie";
alert(name.charAt(0));
this works fine in all browsers.
So something to consider when your coding in JavaScript again.