function CheckText()
{
   // Get ASCII value of key that user pressed
   var key = window.event.keyCode;

   // Was key that was pressed a special character (<*><,>,</>,<!"#$%&'>,<:;<=>?>)?
   if ( key != 42 && key != 44 && key != 47 && key != 33 && key != 34 && key != 35 && key != 36 && key != 37 && key != 38 && key != 39 && key != 58 && key != 59 && key != 60 && key != 61 && key != 62 && key != 63)
      return; // if so, do nothing
   else
      window.event.returnValue = null; // otherwise, discard character
}