/*
	Allows only numbers and control keys in an input field.

	Call: onkeypress="return filterNumbers(event);"
*/
function filterNumbers(e) {
   var key;
   var keychar;

   if (window.event)
      key = window.event.keyCode;
   else if (e)
      key = e.which;
   else
      return true;
   keychar = String.fromCharCode(key);
   
   // control keys
   /*
   8 -> backspace
   9 -> tab
   13-> return
   27-> escape
   */
   if ((key==null) || (key==0) || (key==8) || 
       (key==9) || (key==13) || (key==27) )
      return true;
   
   // numbers
   else if ((("0123456789").indexOf(keychar) > -1))
      return true;
  return false;
}
 /*
 IE only
 */
function noenter() {
	return (!(window.event && window.event.keyCode == 13)); 
}

 /*
 IE only
 */
function noenter(e) {
    var key;
    if (window.event)
      key = window.event.keyCode;
   else if (e)
      key = e.which;
   else
      return true;
	
	return (!(key == 13)); 
}

function cartQuantityFilter(e) {
   return (filterNumbers(e) && noenter());

}