Hi Pero,
Thanks for your support, I create a fresh master page it works fine however the current master page does not work.
Here is the code of master page
<%
@ Master Language="C#" AutoEventWireup="true" CodeBehind="Base.master.cs" Inherits="PersonalPortal.Pages.Base" %>
<%
@ Register assembly="Telerik.Web.UI" namespace="Telerik.Web.UI" tagprefix="telerik" %>
<!
DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<
html xmlns="http://www.w3.org/1999/xhtml" >
<
head runat="server">
<title>Untitled Page</title>
<asp:ContentPlaceHolder ID="head" runat="server">
</asp:ContentPlaceHolder>
<meta http-equiv="Page-Enter" content="revealtrans(duration=0.0)" />
<meta http-equiv="Page-Exit" content="revealtrans(duration=0.0)" />
</
head>
<
body >
<form id="form1" runat="server">
<telerik:RadScriptManager ID="RadScriptManager1" Runat="server">
</telerik:RadScriptManager>
<telerik:RadFormDecorator ID="RadFormDecorator1" Runat="server"
Skin="Windows7" />
<telerik:RadAjaxManager ID="RadAjaxManager1" runat="server" >
</telerik:RadAjaxManager>
<table style="width:100%;">
<tr>
<td>
<table align="center" class="BodyTable" border="0" >
<tr>
<td align="center" valign ="top">
<asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td align="center">
<asp:Label ID="Label1" runat="server" Text="eCare 2009 Copyright"></asp:Label>
</td>
</tr>
</table>
</form>
</
body>
</
html>
Regards,
Duy