function checkForm(doc) {
	var form = doc.form;
	if (form.August14.checked == false && form.August15.checked == false && form.August16.checked == false) {
		alert("Please register for at least one day");
		form.August14.focus();
		return;
	}
	
	if (form.name.value == '') {
		alert("Please enter a name");
		form.name.focus();
		return;
	}
		
	var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
	if (!form.email.value.match(emailExp)) {
		alert("Please enter a valid email address");
		form.email.focus();
		return;
	}
	
	if (form.affiliation.value == '') {
		alert("Please enter an affiliation");
		form.affiliation.focus();
		return;
	}
	
	form.submit();
}