function checkOrderForm(f){
	if(!f.fullName.value.length){
		alert('Please enter your name');
		f.fullName.focus();
		return false;
	}
	if(!checkMail(f.email.value)){
		alert('Please enter a valid email address');
		f.email.focus();
		return false;
	}
	if(!f.phone.value.length){
		alert('Please enter your phone number');
		f.phone.focus();
		return false;
	}
	if(!f.delivery[0].checked && !f.delivery[1].checked){
		alert('Please select your delivery method');
		return false;
	}
	if(f.delivery[1].checked){
		if(f.mailingAddr.value.length < 10){
			alert('Mailing address is required when deliver method is "by mail"');
			return false;
		}
	}
	return true;
}

function checkContactForm(f){
	if(!f.fullName.value.length){
		alert('Please enter your name');
		f.fullName.focus();
		return false;
	}
	if(!checkMail(f.email.value)){
		alert('Please enter a valid email address');
		f.email.focus();
		return false;
	}
	if(!f.inquiry.value.length){
		alert('Please enter your inquiry');
		f.inquiry.focus();
		return false;
	}
	return true;
}


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