function fensteroeffnen (WindowURL, opener, breite, hoehe) {
  var title = "default";
  title = Date.parse(new Date());
  var pp = window.open(WindowURL, title, opener);
  pp.moveTo((screen.availWidth - breite) / 2,(screen.availHeight - hoehe) / 2);
}

function suchergebnis(url) {
    var title = "default";
    title = Date.parse(new Date());
    var pp = window.open(url, title, 'width=450,height=400,toolbar=0,titlebar=0,location=no,status=0,menubar=0,scrollbars=1,resizable=1');
    pp.moveTo(10, 10);
}

function popupDialog(url) {
    fensteroeffnen(url, 'width=800,height=600,toolbar=0,titlebar=0,location=no,status=0,menubar=0,scrollbars=1,resizable=1', 800, 600);
}

function karte(url) {
    fensteroeffnen(url, 'toolbar=0,fullscreen=0,maximize=0,titlebar=0,location=no,directories=0,status=0,menubar=0,scrollbars=1,resizable=1,width=350,height=550', 350,550);
}

function zoom(url) {
    fensteroeffnen(url, 'toolbar=0,fullscreen=0,maximize=0,titlebar=0,location=no,directories=0,status=0,menubar=0,scrollbars=1,resizable=1,width=800,height=600', 800,600);
}

function exposeVorschau(url) {
    fensteroeffnen(url, 'toolbar=0,fullscreen=0,maximize=0,titlebar=0,location=no,directories=0,status=0,menubar=0,scrollbars=1,resizable=1,width=900,height=600', 900,600);
}

function checkFormular(formname) {
  with(document.forms[formname]) {
    vDate = new Date(vJahr.value,vMonat.value-1,vTag.value);
    bDate = new Date(bJahr.value,bMonat.value-1,bTag.value);
    if (Date.parse(vDate) > Date.parse(bDate)) {
        alert("Bitte waehlen Sie einen gueltigen Zeitraum aus.");
        return false;
    }
  }
}

function checkSuchFormular() {
  with(document.forms['suche']) {
    vDate = new Date(vJahr.value,vMonat.value-1,vTag.value);
    bDate = new Date(bJahr.value,bMonat.value-1,bTag.value);
    if ((Date.parse(vDate) > Date.parse(bDate)) || (Date.parse(vDate) == Date.parse(bDate))) {
        alert("Bitte waehlen Sie einen gueltigen Zeitraum aus.");
        return false;
    }
  }
}