WebForm_InitCallback();Sys.Application.add_init(function() {
    $create(Telerik.Web.UI.RadComboBox, {"_dropDownWidth":0,"_showDropDownOnTextboxClick":false,"_skin":"Office2007","_uniqueId":"ctl00$ContentPlaceHolder1$RetailComponentControl1$ddlFrom","allowCustomText":true,"clientStateFieldID":"ctl00_ContentPlaceHolder1_RetailComponentControl1_ddlFrom_ClientState","collapseAnimation":"{\"type\":12,\"duration\":200}","enableLoadOnDemand":true,"itemData":[],"text":"","value":"","webServiceSettings":"{\"path\":\"/CallbackWebServices/ComboBoxLists.asmx\",\"method\":\"AirportList\"}"}, {"itemsRequesting":itemRequesting}, null, $get("ctl00_ContentPlaceHolder1_RetailComponentControl1_ddlFrom"));
});



Could I just manually add this and make it work?

Prometheus vs Rad. 

In Rad I was able to use

    ClientScript.RegisterStartupScript(cstype, "", " AjaxNS.AR('ctl00$ContentPlaceHolder1$Buttonx', '', 'ctl00_ContentPlaceHolder1_RadAjaxPanel1', event); ", true);

to Submit my page back to itself.  I am creating some images for the user and want to show the loading panel while the work is being done.  When the image finish creating the "Loading" would disapear. 

With Prometheus I can get the page to submit back to itself, but the loading panel does not appear.
I have tried:
ClientScript.RegisterStartupScript(cstype, "", " 'ctl00_ContentPlaceHolder1_Buttox.click(); ", true);

ScriptManager.RegisterStartupScript(Buttonx, cstype, "", " 'ctl00_ContentPlaceHolder1_Buttox.click(); ", true);

If I disable the start up script and just click the button the loading panel does appear. 

I can tell that is it is not firing the OnRequestStart event of the loading panel. 

What I am trying to accomplish is that the page loads - then automaticly post back to it self showing the loading panel.  Generate some user images in the code behind of the button click.  show the images - then hide the loading panel. 

Any help would be appreciated.