function centerPopup(popup_name,popup_url,popup_width,popup_height,scrolls, menubars, myWidth, myHeight,reqURL)
{
 if(!myWidth) {myWidth = 10;}
 if(!myHeight){myHeight = 50;}
 if(!scrolls){scrolls = 'no';}
 if(!menubars){menubars = 'no';}
 var popup_left = (window.screen.width/2) - (popup_width/2 + myWidth);
 var popup_top = (window.screen.height/2) - (popup_height/2 + myHeight);
 var fenster = window.open(popup_url ,popup_name,"toolbar=no,location=no,status=no,menubar=" + menubars + ",scrollbars=" + scrolls + ",resizable=no,width=" + popup_width + ",height=" + popup_height + ",left=" + popup_left + ",top=" + popup_top + ",screenX=" + popup_left + ",screenY=" + popup_top);
 fenster.focus();
}

function submitForm(el) {
	elem = document.getElementById(el);
	v = elem.value;
    if (v.length == 0) {
		alert("Sie müssen eine gültige Email Adresse eingeben!");
    } else {
		i = v.indexOf("@");
		if (i <= 0) {
			alert("Sie müssen eine gültige Email Adresse eingeben!");
		} else {
			return true;
		}
	}
	elem.focus();
    return false;
}