VS 2008 Determine Postback Element?

Is there a way where I can actually view the name of a post back element? Below code goves me an alert but all it says is "object HTMLSelectElement". In my case it should be DropDownList3 based upon a "selectedindexchanged" event with autoppostback=true.

Code:
var pbControl = null;
pbControl = args.get_postBackElement();
alert(pbControl);
var ExecutingControl = "DropDownList3"
if (ExecutingControl == pbControl) {
alert("DropDownList3 - is the post back element");