telerik - RadAjaxManager problem when showing/hiding control on page loading -

I have a webform with dropdown list, labels and textbox as follows:

  & Lt; Asp: dropdown list id = "ddlTest" runat = "server" autopost = "true" & gt; & Lt; / ASP: DropDownList & gt; & Lt; Asp: Label ID = "lblTest" runat = "server" text = "some text" & gt; & Lt; / ASP: Labels & gt; & Lt; Asp: text box id = "edtTest" runat = "server" & gt; & Lt; / ASP: text box & gt;  

I want to show / hide the label / text box based on the selected value in the dropdown list. That's why I've added RadAjaxManader:

   & Lt; Rad: AjaxUpdatedControl ControlID = "edtTest" /> & Lt; / UpdatedControls & gt; & Lt; / Red: AjaxSetting & gt; & Lt; / AjaxSettings & gt; & Lt; / Red: RadAjaxManager & gt;  

And "Setup Upsability", which takes value from the dropdown list, does some futures and explains whether to show or hide the label and text box. When I use this kind of process:

  Protected sub ddlTest_SelectedIndexChanged (ByVal handles this form, as byVal e System.EventArgs) ddlTest.SelectedIndexChanged SetupVisibility () End Sub < / Code> 

This works well, but now I want to call SetupVisibility, when page load calls:

  protected sub page_Load (ByVal As this object, ByVal E. System.EventArgs handles as me. Load SetupVisibility () End Sub  

There is a problem in this scenario.

1. SetupVisibility () hides the text box and label while the page loads
2. Change the value to the ddlTest dropdown list
3. SetupVisibility () text box And labels, but wants to show again > I:. Microsoft JScript - Order Error: Can not update control with id: ctl00_CPH1_lblTest control does not exist. Where is the problem?

I 've solved the problem I have written the text box and the label in the div and panel Is wrapped up:

  & lt; Div id = "panelTest_DIV" runat = "server" & gt; & Lt; ASP: Panel ID = "PanelTest" Runat = "Server" & gt; & Lt; Asp: label id = "lblteest" runat = "server" text = "some text ..." & gt; & Lt; / Asp: label & gt; & Lt; Br / & gt; & Lt; Asp: text box id = "edtTest" runat = "server" & gt; & Lt; / Asp: text box & gt; & Lt; / ASP: Cell & gt; & Lt; / Div & gt;  

and AjaxManager:

  & lt; Red: AjaxSetting AjaxControlID = "ddlTest" & gt; & Lt; UpdatedControls & gt; & Lt; Rad: AjaxUpdatedControl ControlID = "panelTest_DIV" /> & Lt; / UpdatedControls & gt; & Lt; / Red: AjaxSetting & gt;  

inside SetupVisibility () I set panelTest.Visibility . Resolved this problem.