if (screen.width>1280){
    with(document.getElementById('pic_right_div')){
         innerHTML='<img src="../images/Bild_1b_340.jpg" alt="" />';
         style.position='fixed';
         style.right=(screen.width-1395)+'px';
         }
    }else if (screen.width>1024){
    with(document.getElementById('pic_right_div')){
         innerHTML='<img src="../images/Bild_1b_240.jpg" alt="" />';
         style.position='fixed';
         style.right=(screen.width-1275)+'px';
         }
    }