function RefreshImage(imgId, imageUrl, duration) {
    var imgElement = jQuery("#" + imgId);
    if(imgElement != undefined)
    {
        tmp = new Date(); 
        tmp = "?"+tmp.getTime();
        imgElement.attr("src",imageUrl+tmp);
    }
    setTimeout(function(){
        RefreshImage(imgId, imageUrl, duration)
    },duration*1000);
}