function grossbild(bild)
{
bildsrc = "grossbild.html?"+bild;
/*window.location.href=bildsrc;*/
var win;
win = window.open (bildsrc,"bigpic","width=740px,height=640px,resize=no");

 x = screen.height;
 weite = new Array(1152,1024,800)
 if (x > 768 && x <= 864)
{screen_weite = weite[0];}
else
 if (x > 600 && x <= 768)
{screen_weite = weite[1];}
else
{screen_weite = weite[2];}

target_y = (x-640)/2;
if (target_y <= 0)
{y_wert = 0;}
else
{y_wert = target_y;}
target_x = (screen_weite-740)/2;
win.moveTo(target_x,y_wert);
win.focus();
}