function show(layerid) {
	document.getElementById(layerid).style.visibility = 'visible';
}

function hide(layerid) {
	document.getElementById(layerid).style.visibility = 'hidden';
} 

function checkForm() {
	var fehler = "";
	document.getElementById('errorname').style.display='none';
	document.getElementById('erroremail').style.display='none';
	document.getElementById('errormessage').style.display='none';
	
	if (document.forms[0].name.value=="") {
		document.getElementById('errorname').style.display='block';
		fehler = "1";
	}
	if (document.forms[0].email.value=="") {
		document.getElementById('erroremail').style.display='block';
		fehler = "1";
	}
	if (document.forms[0].message.value=="") {
		document.getElementById('errormessage').style.display='block';
		fehler = "1";
	}
	if (fehler == "1") {
		return(false);
	}
}

function checkFormNewsletter() {
	var fehler = "";
	document.getElementById('error').style.display='none';	
	if (document.newsletter_eintragen.newsletter.value=="" || document.newsletter_eintragen.newsletter.value=="max@mustermann.de") {
		document.getElementById('error').style.display='block';
		fehler = "1";
	}
	if (fehler == "1") {
		return(false);
	}
}