var popup;
var top = this;
function zoom(img,w,h)
{
      if(popup != null && false == popup.closed) popup.close();
      popup = window.open('fkzoom.php?image=' + img,'zoom'+img,'height='+h+',width='+w);
}

function popup_zoom(event,next,previous,nw,nh,pw,ph,w,h)
{
      mx=(event).clientX;

      if(popup != null && false == popup.closed) popup.close();
      if(mx > (w / 2)) 
            popup = window.open('fkzoom.php?image=' + previous,'zoom'+previous,'height='+ph+',width='+pw);                        
      else
            popup = window.open('fkzoom.php?image=' + next,'zoom'+next,'height='+nh+',width='+nw);            

}