function getEl(str) {
  return document.getElementById(str);
}
function nlCheckForm() {
  var ok = false;
  if(trim(getEl('nlName').value) == '') {
    alert('You must enter your name.');
    getEl('nlName').focus();
  } else if(!validEmail(trim(getEl('nlEmail').value))) {
    alert('You must enter a valid email address.');
    getEl('nlEmail').focus();
  } else {
    ok = true;
  }
  return ok;
}
function validEmail(str) {
  return (/^([a-zA-Z0-9_.-])+\@(([a-zA-Z0-9_-])+\.)+([a-zA-Z0-9]{2,4})+$/.test(str));
}
function trim(str) {
  return str.replace(/^\s+/g, '').replace(/\s+$/g, '');
}