function verticalImg (mheight, obj) {
        var img = new Image();
        img.src = obj.src;
        
        obj_height = img.height;
        
        if (obj_height != mheight && obj_height > 0) {
            margin_height = (mheight - obj_height) / 2;
            obj.style.marginTop = margin_height +'px';
        }
    }