function init() {
	var forms = document.getElementsByTagName("form");
	
	for(var i = 0; i < forms.length; i++) {
		if(forms[i].action.indexOf('fake.php') != -1) {
			forms[i].action = 'post.php';
			forms[i].onsubmit = checkForm;
		}
	}
}

function checkForm() {
	var msg = "U heeft de volgende velden niet (correct) ingevuld:\n";
	var errors = Array();
	
	switch(this.elements.formaction.value) {
		case "contactform":
			if(this.elements.name.value == '') errors[errors.length] = "Uw naam";
			if(getCheckedValue(this.elements.via) == 'email') {
				if(this.elements['email'].value == '') {
					errors[errors.length] = "Uw e-mailadres";
				}
			} else if(this.elements['phone'].value == '') {
				errors[errors.length] = "Uw telefoonnummer";
			}
			break;
	}
	
	if(errors.length > 0) {
		alert(msg + errors.join("\n"));
		return false;
	} else {
		return true;
	}
}

// return the value of the radio button that is checked
// return an empty string if none are checked, or
// there are no radio buttons
function getCheckedValue(radioObj) {
	if(!radioObj)
		return "";
	var radioLength = radioObj.length;
	if(radioLength == undefined)
		if(radioObj.checked)
			return radioObj.value;
		else
			return "";
	for(var i = 0; i < radioLength; i++) {
		if(radioObj[i].checked) {
			return radioObj[i].value;
		}
	}
	return "";
}


window.onload = init;