function checkForm(){
	
	var emailExpression = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
   var msg="";
	
	if (document.contactform.name.value == "") {
     	msg=msg+"Please enter your name\n";
	}
	if (document.contactform.telephone.value == "" && document.contactform.email.value == "") {
     	msg=msg+"Please enter either a telephone number or email address\n";
	}
	if (document.contactform.message.value == "") {
     	msg=msg+"Please enter your message or question\n";
	}
	if (document.contactform.email.value != "") {
		if (! document.contactform.email.value.match(emailExpression)) {
    	msg=msg+"Email address incorrectly formatted\n";
		}
	}
	
	if (msg) {
		alert(msg)
		return (false)
	} else {
		return (true);
	}	
}