document.oncontextmenu = new Function("return false;");
document.ondragstart = new Function("return false;");
document.onselectstart = new Function("return false;");

function CheckFieldLength(fn, rn, max) 
{
  var len = fn.value.length;
  
  if (len > max) {
    fn.value = fn.value.substring(0, max);
    len = max;
  }
  document.getElementById(rn).innerHTML = max - len;
}