function isEmailValid(em)
{
  var p1=em.indexOf('@'), p2=em.lastIndexOf('.'), l=em.length; 
  return (p1 > 0) && (p2 > p1+1) && (p2 < l-1); 
}

function checkContactUsForm()
{
  var o, sErrMsg="";
  o = fo('name');
  if (o.value == "") {
    sErrMsg+="* Username is a required field.\n";
  }
  o = fo('email');
  if (!isEmailValid(o.value)) {
    sErrMsg+="* Enter your valid email address.\n";
  }
  o = fo('message');
  if (o.value == "") {
    sErrMsg+="* Description is a required field.\n";
  }
  var bOK = (sErrMsg=="");
  if (!bOK) alert(sErrMsg);
  return bOK;
}