function OperatingSystemSelectorValidatorEvaluateIsValid(val)
{
  var v = ValidatorGetValue(val.DropDownId )
  
    if( (v == "") || (v == "undefined")  )
    Get(val.lblError).innerHTML  = " - Required";
  else
    Get(val.lblError).innerHTML  = "";
    
    
  return !( (v == "") || (v == "undefined")  )
}