Ajax not working in IE9 compatibility mode:

In web development there is nothing more frustrating than cross browser compatibility, having to hack up your code so it will work in IE 7, IE 6?, compatibility mode, etc... ugh.

Real quick, cross browser compatibility is a term used to describe a website and coding that looks and functions the same in all web browsers. Safari, Fire Fox, Internet Explorer, etc. etc.

The other day I ran into an issue with Drupal, Ajax, jQuery and IE 9 compatibility mode not loading the content after clicking a menu item. It went as far as making the div container visible. A colored block in the middle of nowhere with no content or anything inside it. The frustrating part is that this functionality is working fine in Safari, Fire Fox, even IE9 in regular mode!

So I run through some basic troubleshooting to find out what part of the code is causing problems. At first I automatically assume that it has to do with the jQuery / javascript coding; I've had issues with IE and javascript before. SO I spent some time rummaging through the js file moving chunks of code and deleting to test, then replacing. There are two ajax calls involved I narrowed it down to one of the links and eventually found the error in the php code. In the end it was an extra closing div tag.