if (document.images)
    {
        preload_image_object = new Image();
        // set image url
        image_url = new Array();
        image_url[0] = "/img/RectRollOver.png";
        image_url[1] = "/img/RectRollOut.png";
        image_url[2] = "/img/RectRollOut.png";
        image_url[3] = "/x.png";        
        image_url[4] = "/img/RectRollSmallOut.png";
        image_url[5] = "/img/RectRollSmallOver.png";        
        image_url[6] = "/img/indicator_verybig.gif";
        var i = 0;
        for(i=0; i<=12; i++)  {
            preload_image_object.src = image_url[i];
        }            
    }