function tb_remove_ext() {
    eval_script(mark_read_url);
}

$(document).ready(function(){   
    if (msg_url != null && msg_url != "") {
        imgLoader = new Image(); // preload image
	    imgLoader.src = tb_pathToImage;
        msg_url += msg_url_params;
        tb_show(tb_caption, msg_url, tb_imgGroup);
    }
});