function validateForm() {
	var err = 0;
	
	if(document.getElementById("Vorname").value == '') {
		document.getElementById("label-vorname").className = 'error required';
		err = 1;
	} else {
		document.getElementById("label-vorname").className = '';
	}
	
	if(document.getElementById("Name").value == '') {
		document.getElementById("label-name").className = 'error required';
		err = 1;
	} else {
		document.getElementById("label-name").className = '';
	}
	
	if(document.getElementById("Telefon").value == '') {
		document.getElementById("label-telefon").className = 'error required';
		err = 1;
	} else {
		document.getElementById("label-telefon").className = '';
	}
	
	if(document.getElementById("Nachricht").value == '') {
		document.getElementById("label-nachricht").className = 'error required';
		err = 1;
	} else {
		document.getElementById("label-nachricht").className = '';
	}
	
	if(err === 0) {
		return true;
	} else {
		document.getElementById("fehlermeldung").style.display = 'block';
		return false;
	}
		
}

function isMailValid() {
	if (document.getElementById("E-Mail").value != '' && !document.getElementById("E-Mail").value.match(/^[\w\.\-]+@([\w\-]+\.)+[a-zA-Z]+$/)) {
		document.getElementById("label-mail").className = 'error';
		return false;
	} else {
		document.getElementById("label-mail").className = '';
		return true;
	}
}