popup clander and ToolkitScriptManager problem

hi everybody
i build register page in my page i use ToolkitScriptManager where i can chick username and email if it used  by another one or not the problem is when i chick user and email the clander never work if make refresh to the page and choose the clander frist before chick user and email it works fine and even my gif loading never work and also any javascrpit message of save or not doesnt work it try many time  but no sense
my code is
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="register.ascx.cs" Inherits="UserControl_register" %> <%@ Register assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagprefix="asp" %> <script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script> <script src="Scripts/jquery.dynDateTime.min.js" type="text/javascript& ...