function popup(w,h,site) {
    x = screen.availWidth/2-w/2;
    y = screen.availHeight/2-h/2;
    popupWindow = window.open('js/pictureResized.php?path='+site,'','width='+w+',height='+h+',left='+x+',top='+y+',screenX='+x+',screenY='+y);
}