var contactForm;
var falseForm;

function init() {
	
	contactForm = document.getElementById('contactus');
	
	contactForm.onsubmit = function () {
		return canSubmit(this);
	}
}

function filled(field) {
	if (field.value == "" || field.value == null) {
		return false;
	} else {
		return true;
	}
}

function canSubmit(form) {
	falseForm = true;
	
	if (!filled(form.Name)) {
		form.nameError.value = "Please enter your name"
		falseForm = false;
	}	else {
		form.nameError.value = ""
	}

	var atIndex=form.Mail.value.indexOf("@");
	var dotIndex=form.Mail.value.lastIndexOf(".");

	if (!filled(form.Mail)|| atIndex<1||dotIndex-atIndex<2) {
		form.mailError.value = "Please enter a valid email address"
		falseForm = false;
	}	else {
		form.mailError.value = ""
	}
	
	if (!filled(form.Subject)) {
		form.subjectError.value = "Please enter a subject"
		falseForm = false;
	}	else {
		form.subjectError.value = ""
	}

	if (!filled(form.Body)) {
		form.bodyError.value = "Please enter a message"
		falseForm = false;
	}	else {
		form.bodyError.value = ""
	}
	
	return falseForm
}