If you’re ever doing some AJAX stuff with a text-box input it’s possible that your Firebug will throw a very unusual error:
Error: [Exception… “‘Permission denied to get property XULElement.selectedIndex’ when calling method:
The problem lies in Firefox specifically and it’s autocomplete functionality. To fix it all you need to do is update your input field with the following code:
<input type=”text” autocomplete=”off”>
The autocomplete bit of code stops Firefox from attempting to complete the content in the box (thus throwing off the DOM or something). It’s not XHTML 1.0 transitional complient but it does stop Firefox from throwing errors.