function numeric(obj, event)
{
   var key;
   var keyChar;

   if (window.event)
      key = window.event.keyCode;
   else if (event)
      key = event.which;
   else
      return true;

   keyChar = String.fromCharCode(key);

   if ((key==null) || (key==0) || (key==8) || (key==9) || (key==13) || (key==27) )
      return true;
   else if ((("1234567890").indexOf(keyChar) >= 0 ))
      return true;

   return false;
}