function validate_required(field,alerttxt) {
	with (field) {
		if (value==null||value=="") {
			alert(alerttxt);return false;
		} else {
			return true;
		}
	}
}
function validate_email(field,alerttxt) {
	with (field) {
		apos=value.indexOf("@");
		dotpos=value.lastIndexOf(".");
		if (apos<1||dotpos-apos<2) {
			alert(alerttxt);
			return false;
		} else {
			return true;
		}
	}
}

function validate_form(thisform) {
	with (thisform) {
		if (validate_required(naam,"Name required!")==false) {
			naam.focus();
			return false;
		}
		if (validate_required(postcode,"Postal code required!")==false) {
			postcode.focus();
			return false;
		}
		if (validate_required(gemeente,"City required!")==false) {
			gemeente.focus();
			return false;
		}
		if (validate_required(tel,"Please leave your telephone number and we will contact you.")==false) {
			tel.focus();
			return false;
		}
		if (validate_email(email,"Not a valid email address!")==false) {
			email.focus();
			return false;
		}
	}
}

function switchAfspraak(value) {
	if(value) {
		document.getElementById('afspraak_bellen').style.display = "block";
	} else {
		document.getElementById('afspraak_bellen').style.display = "none";
	}
}