how to use multiple tinymce on page in asp net?

Hi all.

My tinymce inside user control and I use 3 tinymce in one page. My tinymce inside update panel and i use mode: 'exact' for tinymce setting. I don't want to use mode: "textareas" for tinymce. When i run my project only 1 tinymce (OtherDescTBX) load and other tinymce does not show. What is my problem and How to solve this problem?

Note:

1- My tinymce inside user control.

2- use ValidateRequest="false" for page.

3- use <httpRuntime requestValidationMode="2.0" /> in web.config.

4- use ScriptManager on masterpage.

Thank you for help.

My tinymcy code:

<script runat="server">
        public TextBox SetSize { get { return txtContent; } }

        public HiddenField getHiddenField { get { return HiddenField1; } }
</script>

<script type="text/javascript" src="editors/tiny_mce/tiny_mce.js"></script>
<script type="text/javascript">
   $(function () { LoadTinyMCE(); });
   var prm = Sys.WebForms.PageRequestManager.getInstance();
   prm.add_endRequest(function (sender, e) { LoadTinyMCE(); });
   function LoadTinyMCE() {
      tinyMCE.init({
         // General options 
         mode: "exact",
         elements: "<%=txtContent.ClientID %>",
         theme: "advanced",
         plugins: "autolink,lists,pagebreak,style,layer,table,save",
 
         // Theme options
         
         // Example content CSS (should be your site CSS)
         
        // Drop lists for link/image/media/template dialogs
        
       // Style formats
       
      // Replace values for the template plugin
      template_replace_values: {
           username: "Some User",
           staffid: "991234"
       },
       setup: function (ed) { ed.onChange.add(function (ed, l) { $('[id*=HiddenField1]').val(l.content); });
    }
   });
}
</script>

<asp:TextBox runat="Server" ID="txtContent" CssClass="post" Width="100%" Height="550px" TextMode="MultiLine" />
<asp:HiddenField ID="HiddenField1" runat="server" />

My aspx page:

<%@ Register Src="UserControls/tinymce.ascx" TagPrefix="Blog" TagName="TextEditor" %>

<asp:UpdatePanel runat="server" ID="UpdatePanel2"><ContentTemplate>
<table align="center">
<tr>
<td align="right"><asp:TextBox ID="ShortDescTBX" runat="server" CssClass="ManagerTBX" Width="350px" Height="60px" TextMode="MultiLine"></asp:TextBox></td>
<td align="right"><asp:Label ID="Label3" runat="server" CssClass="ManagerLBL" Width="110px" Text="Short Desc :"></asp:Label></td>
</tr>
<tr>
<td align="right" colspan="2"><Blog:TextEditor runat="server" id="CompleteDescTBX" /></td>
<td align="right"><asp:Label ID="Label6" runat="server" CssClass="ManagerLBL" Width="110px" Text="Complete Desc :"></asp:Label></td>
</tr>
<tr>
<td align="right" colspan="2"><Blog:TextEditor runat="server" id="TechnicalDescTBX" /></td>
<td align="right"><asp:Label ID="Label9" runat="server" CssClass="ManagerLBL" Width="110px" Text="Technical Desc :"></asp:Label></td>
</tr>
<tr>
<td align="right" colspan="2"><Blog:TextEditor runat="server" id="OtherDescTBX" /></td>
<td align="right"><asp:Label ID="Label10" runat="server" CssClass="ManagerLBL" Width="110px" Text="Other Desc :"></asp:Label></td>
</tr>
</table>
</ContentTemplate></asp:UpdatePanel>

My aspx code page:

if (((ScriptManager)this.Page.Master.FindControl("ScriptManager1")).IsInAsyncPostBack)
{
        CompleteDescTBX.Text = Request.Form[CompleteDescTBX.getHiddenField.UniqueID];
        TechnicalDescTBX.Text = Request.Form[TechnicalDescTBX.getHiddenField.UniqueID];
        OtherDescTBX.Text = Request.Form[OtherDescTBX.getHiddenField.UniqueID];
}