I can't understand why in Opera and IE the following code does not work...

$("#form_" + $(this).attr('id')).serialize();

I checked it by only getting the attribute; worked
I checked if I could get the form data without serialize; worked

How should I code this? Tried a lot of combinations and stuff but nothing works.. why does this isn't working in opera? In chrome I have no problems...

To answer some of the questions below

I have multiple forms on my page, each with an unique id (from_1, form_5 etc.) I checked this and is correct. The form data needs to be fetched when a select changes, so data call is fired by an change event.