function validate_form(thisform) {
	var flag=0;
	with (thisform) {
		if (eMail.value==null || eMail.value=="" ) {
			document.getElementById('email_label').style.color="red";
			eMail.focus();
			flag=1;	
		} else {
			apos=eMail.value.indexOf("@");
			dotpos=eMail.value.lastIndexOf(".");
			if (apos<1||dotpos-apos<2) {
				document.getElementById('email_label').style.color="red";
				document.getElementById('alert').style.display="block";
				eMail.focus();
				flag=1;	
			}
			else { 
				document.getElementById('email_label').style.color="";
				document.getElementById('alert').style.display="none";
			}	
		}
		if (Nachname.value==null || Nachname.value=="" ) {
			document.getElementById('nachname_label').style.color="red";
			Nachname.focus();
			flag=1;	
		} else {
			document.getElementById('nachname_label').style.color="";
		}
		if (Vorname.value==null || Vorname.value=="" ) {
			document.getElementById('vorname_label').style.color="red";
			Vorname.focus();
			flag=1;	
		} else {
			document.getElementById('vorname_label').style.color="";
		}
		if (flag) {return false;}
		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;}
}
}