var fenstertitle;
var win;
var br;
var hoe;
var x;
var y;

function fensterauf(fenstertitle ,br, hoe)
{
fenstertitle += '.htm';
win = window.open(fenstertitle, "", "menubar=no, directories=0, resizable=no, scrollbars=no, status=no, titlebar=no, toolbar=no, location=no");
win.resizeTo(br, hoe);
x = (screen.width - br)/2;
y = (screen.height - hoe)/2;
win.moveTo(x,y);
}