use script manager and UpdateProgress

hi

i use UpdateProgress control

and i add a user control dynamic below like in a button :

Control pageCtrl = new Control();
        pageCtrl = LoadControl("UserControl" + idStatistical.Trim() + ".ascx");
        divResult.InnerHtml = "";
        divResult.Controls.Add(pageCtrl);

when i run it for first, run correct .but when i run it for second the user control first add but divresult don't update 

please help me for solve it

thanks