function isInteger(theElement, theElementName)
{
  var s = Math.abs(theElement.value);
  var filter=/(^\d+$)/;
  if (s.length == 0 ) return true;
  if (filter.test(s))  
       return true;
  else  
         alert(" Please input a valid Integer Value!" );
    theElement.focus(); 
    theElement.select(); 
    return false;
}