update panel in content page works just on first time click?

[2208]

i want to use ajax in content page i have script manager on master page in content page i have following code <asp:Content ID="Content2" ContentPlaceHolderID="MainContents" runat="server" EnableViewState="true"> <asp:ScriptManagerProxy ID="ScriptManagerProxy1" runat="server"> </asp:ScriptManagerProxy> <asp:CheckBox ID="CheckBox1" runat="server" OnCheckedChanged ="checkchange" AutoPostBack ="true"/> <asp:UpdatePanel ID="updatePnl" runat="server" UpdateMode="Conditional"> <ContentTemplate> <asp:TextBox ID="TextBox1" runat="server" visible="false" ></asp:TextBox> <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="CheckBox1" /> </Triggers> </asp:UpdatePanel> </asp:Content> on server side i have following protected void checkchange(object sender, EventArgs e) { if (CheckBox1.Checked) { TextBox1.Visible = true; Label1.Text = Label1.Text + "HEllo"; } else { TextBox1.Visible = false; Label1.Text = Label1.Text + "bye"; } } problem is checkchange call just once if i click towice on check box it does not works

[Jeroenh]

Put the checkbox inside the updatepanel

[2208]

i have try this but same problem and error is Webpage error details User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.2; .NET4.0C; .NET4.0E) Timestamp: Mon, 26 Jul 2010 10:19:37 UTC Message: Unknown runtime error Line: 345 Char: 9 Code: 0 URI: http://localhost:4099/ScriptResource.axd?d=9I1lWtAvVqWN1mD9glifsmEaMOiOLiTKjnBQwe4NQFLjuZpRoCN\_LRiI-oQlHO1ffCWMttDUGTSGUEn\_n-0ZNQXbP7japojTJ\_LVrzCwdLJYzGHv0-QESNieL9JuFlAo0&t=ffffffffec2d9970 Message: '__EVENTTARGET' is null or not an object Line: 482 Char: 9 Code: 0 URI: http://localhost:4099/ScriptResource.axd?d=9I1lWtAvVqWN1mD9glifsmEaMOiOLiTKjnBQwe4NQFLjuZpRoCN\_LRiI-oQlHO1ffCWMttDUGTSGUEn\_n-0ZNQXbP7japojTJ\_LVrzCwdLJYzGHv0-QESNieL9JuFlAo0&t=ffffffffec2d9970 Message: '__EVENTTARGET' is null or not an object Line: 482 Char: 9 Code: 0 URI: http://localhost:4099/ScriptResource.axd?d=9I1lWtAvVqWN1mD9glifsmEaMOiOLiTKjnBQwe4NQFLjuZpRoCN\_LRiI-oQlHO1ffCWMttDUGTSGUEn\_n-0ZNQXbP7japojTJ\_LVrzCwdLJYzGHv0-QESNieL9JuFlAo0&t=ffffffffec2d9970 Message: '__EVENTTARGET' is null or not an object Line: 482 Char: 9 Code: 0 URI: http://localhost:4099/ScriptResource.axd?d=9I1lWtAvVqWN1mD9glifsmEaMOiOLiTKjnBQwe4NQFLjuZpRoCN\_LRiI-oQlHO1ffCWMttDUGTSGUEn\_n-0ZNQXbP7japojTJ\_LVrzCwdLJYzGHv0-QESNieL9JuFlAo0&t=ffffffffec2d9970 Message: '__EVENTTARGET' is null or not an object Line: 482 Char: 9 Code: 0 URI: http://localhost:4099/ScriptResource.axd?d=9I1lWtAvVqWN1mD9glifsmEaMOiOLiTKjnBQwe4NQFLjuZpRoCN\_LRiI-oQlHO1ffCWMttDUGTSGUEn\_n-0ZNQXbP7japojTJ\_LVrzCwdLJYzGHv0-QESNieL9JuFlAo0&t=ffffffffec2d9970 Message: '__EVENTTARGET' is null or not an object Line: 482 Char: 9 Code: 0 URI: http://localhost:4099/ScriptResource.axd?d=9I1lWtAvVqWN1mD9glifsmEaMOiOLiTKjnBQwe4NQFLjuZpRoCN\_LRiI-oQlHO1ffCWMttDUGTSGUEn\_n-0ZNQXbP7japojTJ\_LVrzCwdLJYzGHv0-QESNieL9JuFlAo0&t=ffffffffec2d9970 Message: '__EVENTTARGET' is null or not an object Line: 482 Char: 9 Code: 0 URI: http://localhost:4099/ScriptResource.axd?d=9I1lWtAvVqWN1mD9glifsmEaMOiOLiTKjnBQwe4NQFLjuZpRoCN\_LRiI-oQlHO1ffCWMttDUGTSGUEn\_n-0ZNQXbP7japojTJ\_LVrzCwdLJYzGHv0-QESNieL9JuFlAo0&t=ffffffffec2d9970 how i can solve this