// by Brian Lalonde http://webcoder.info/downloads/
// This work is licensed under the Creative Commons Attribution-Share Alike 3.0 License. 
// To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/ 
// or send a letter to Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 94105, USA.

function addOptionIfOther(sel,oprompt)
{
  if((sel.options.length-1)==sel.selectedIndex)
  {
    var other= sel.options[sel.selectedIndex];
    var newval= window.prompt(oprompt,'');
    if(!newval) { sel.selectedIndex= 0; return; }
    sel.options[sel.options.length]= new Option(other.text,other.value,false,false);
    other.text= other.value= newval;
  }
}