loading
beforeSend
<html:view>
<ajax:function name="data" url="/app/ajax" executeOnDocumentLoad="true">
    <ajax:beforeSend>
        /* Available javascript variables ( jqXHR jqXHR, Object settings )*/
         alert(settings);
         alert(jqXHR);
    </ajax:beforeSend>
</ajax:function>
</html:view>