How to submit form when tab or enter key are pressed to change data in a text input box

Hi,

I have a form with a text field.  I want the form to be submitted when the value is updated.  Originally I had the form submit onChange, but if the enter key is pressed instead of tab, the form does not get sumitted.  It is the only text field on the form, so it's very likely someone would enter the new quantity and press enter.

I added the onKeyDown event with this code (found here http://www.experts-exchange.com/Programming/Programming_Languages/Dot_Net/ASP_DOT_NET/Q_21362644.html), but it doesn't work....

function HitEnter()
{
     if(event.KeyCode == 13)
     {
          document.form1.action ="change_qty.cfm";
          document.form1.submit();
          nextCtrl.focus(); // simulate tab key
          event.bubleCancel = true;
          event.returnValue = false; // no more processing..
     }
}

Thanks a lot for any help,
Bonnie