IE Javascript Error: object doesn't support this property or method

Error: Object doesn't support this property or method

I debug the DOM and noticed that none of the extended prototype functions provided by the prototype.js framework (http://prototypejs.org) were register with IE.

No problems with FF (as usual) and other browsers but IE was just not registering the extended functions. After some time debugging I concluded that the error was caused by multiple prototype versions. I didn't have multiple prototype.js files register but instead one of the chat software used in the site had it's own prototype functions that were conflicting with the prototype function $().

Removing the function $() from the chat software solve the problem.

The other solution was to register the prototype.js file at the end of the page so that I will override any other prototype functions registered.


Solution:
Check for multiple prototypes.