function mailCheck()
{

    var filter = /^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/;

    var box = document.forms['bookings'].elements['reqMail'];
	if (!box.value) {
		alert('You haven\'t filled in a valid e-mail address!');
		box.focus();
		return false;
    }
    else  if  (!filter.test(box.value)) {
        alert('Please provide a valid email address');
		box.focus();
		return false;
    }

}