Hi Rohan, I just did a very simple test using jQuery 1.9.1 and it seems to work OK. jQuery 1.9.1 does support the "on" event handler. I'm guessing there is an issue with the selector itself or possibly a timing issue where the item is not in the DOM yet when the Extension runs (at DOM Ready.)
If the item is added to the DOM later, you may need to use the delegated events feature (I haven't done this myself.. yet.. :-) This will be a JS Extension (done in code form) as detailed in their documentation below.
http://api.jquery.com/on/
"Delegated events have the advantage that they can process events from descendant elements that are added to the document at a later time."