function startVR()
{
    var vrHeight = 650;
    var vrWidth = 950;

    var vrLeft = ((screen.availWidth - vrWidth)/2);
    var vrTop = ((screen.availHeight - vrHeight)/2);

    window.open('../tour/html/de/porsche_4447.html', '360_degree_vrtour', 'width=' + vrWidth + ',height=' + vrHeight + ',top=' + vrTop + ',left=' + vrLeft + ',menubar=no,resizable=no, scrollbars=no, toolbar=no');
}