function checkTextAreaLen( fName, theField, maxLen )
{
  if ( theField.value.length > maxLen )
    return msgErrorMid( fName, theField, maxLen, "Please enter less than ", " characters into the  \"", "\"  field. \nCurrently there are " + theField.value.length + " characters in the field." );
  return true;
}
##  and here is the onChange that invokes it from a textarea, limiting to 1500 chars
onChange="checkTextAreaLen(gsJobdesc,this,1500)