function popwin1(url,w,h,s,r)
{
x=screen.width/2;
x=x-w/2;
y=screen.height/2;
y=y-h/2;
popUp=window.open(url,'win','width='+ w +',height='+ h +',left=' + x +',top='+ y +',directories=0,status=0,scrollbars='+s +',resizable='+ r + ',menubar=0,locationbar=0')
}


function popwin2(url,w,h)
{
x=screen.width/2;
x=x-w/2;
y=screen.height/2;
y=y-h/2;
popUp=window.open(url,'win','width='+ w +',height='+ h +',left=' + x +',top='+ y +',directories=1,status=1,scrollbars=1,resizable=1,menubar=1,locationbar=1')
}

function imgwechsel (imgnr, imgobjekt) {
  window.document.images[imgnr].src = imgobjekt.src;
}