function doPostBackAsync(eventName, eventArgs) {
    var prm = Sys.WebForms.PageRequestManager.getInstance();

    if (!Array.contains(prm._asyncPostBackControlIDs, eventName)) {
        prm._asyncPostBackControlIDs.push(eventName);
    }

    if (!Array.contains(prm._asyncPostBackControlClientIDs, eventName)) {
        prm._asyncPostBackControlClientIDs.push(eventName);
    }

    __doPostBack(eventName, eventArgs);
}