function setFocus(e, controlID, nextControlID) {
var evt = e ? e : window.event;
var ctrl = document.getElementById(controlID);   
if (ctrl) {
  var suffix = Right(controlID,4);
  if ((suffix.substring(1) == 'NPA') || (suffix.substring(1) == 'NXX')) {
    if (ctrl.value.length == 3) {
      var nextCtrl = document.getElementById(nextControlID);
      nextCtrl.focus();
      return false;
    }
  }else if (suffix == 'Line') {
    if (ctrl.value.length == 4) { 
      var nextCtrl = document.getElementById(nextControlID);
      nextCtrl.focus();
      return false;
    }
  }      
}
}

function Right(str, n) {
if (n <= 0) {
  return "";
}else if (n > String(str).length) {
  return str;
}else{
  var iLen = String(str).length;
  return String(str).substring(iLen, iLen - n);
} 
}