function openAlert(width, height, file) {
    var window_width = width;
    var window_height = height;
    var window_x = getWindowWidth()/2-window_width/2;
    var window_y = getWindowHeight()/2-window_height/2;

    Dialog.alert({url: file, options: {method: 'get'}}, {className: 'alphacube', top:window_y, left:window_x, width:window_width, okLabel: 'Fenster schliessen'});
}