function checkForm() {
  var OK=false;
  var subject=document.contactForm.subject.value;
  if (subject.length<1) alert("Please provide a subject line.");
  else {
		if (OK=checkName()) {
    	var address=document.contactForm.email.value;
    	OK=checkMail();
  	}
	}
  if (OK) document.contactForm.submit();
}

function checkMail(){
  var emailOK=false;
  if (document.contactForm.email.value.indexOf("@")==-1) alert("No '@' in address.");
  else {
	var adr=document.contactForm.email.value.split("@");
	if (adr[0].length<1) alert("Username absent.");
  	else if (adr[1].indexOf(".")==-1) alert("No dot in domain name.");
  	else {
	  var dmn=adr[1].split(".");
      if (dmn[0].length<3) alert("Domain name too short.");
	  else if (dmn[1].length<2) alert("Domain extension too short.");
      else emailOK=true;
	}
  }
  return emailOK;
}

function checkName() {
  var nameOK=false;
  var name=document.contactForm.realname.value;
  if (name.length<1) alert("Please enter your Name.");
  else nameOK=true;
  return nameOK;
}