function ajaxPost(url_var, data_var, div_var) {

    new Request.HTML({
        url: url_var,
        data: data_var,
        method: 'post',
        evalScripts: true,
        noCache: true,
        onRequest: function() {
            document.id(div_var).set("html", '<div align="center"><img src="/img/ajax-load.gif" /><br/>Loading</div>');
        },
        onComplete: function() {
            var response = this.response.text;
            document.id(div_var).set("tween", {
                onComplete: function() {
                    this.element.set("html", response);
                    this.removeEvents("complete");
                    this.element.fade(1);
                },
                duration: 500
            }).fade(0);
        }
    }).send();

}