function popup(url, theWidth, theHeight){

    if(theHeight==0)
    {
        Shadowbox.open({
            content: url,
            player: "iframe",
            width: theWidth
        });
    }
    else
    {
        Shadowbox.open({
            content: url,
            player: "iframe",
            width: theWidth,
            height: theHeight
        });        
    }

}