APEX

All,
iam using below code and its working good with page submit button but i need it for a page load i.e when a page loads show the progress bar(page which take a while to load) so i can call it like onload. Anybody who has done this pls i appreciate if you could help...

function html_Submit_Progress(pThis){
$x_Show('AjaxLoading');
window.setTimeout('$s("AjaxLoading",$x("AjaxLoading").innerHTML)', 900);
doSubmit('APPLY_CHANGES');
}

function submit_HideAll(pThis){
$x_Hide('wwvFlowForm');
doSubmit('APPLY_CHANGES');
}

function submit_ButtonRegion(pThis){
$x_Hide('button_region');
doSubmit('APPLY_CHANGES');
}

using apex 4.1 and my page here i need it is a popup.
thanks