I guess no one take an effort to resolve this issue but let me give it a try and lets see if you like this explanation. Okay?
First you have to create a masterpage and your master page must look like this.
<%@ Master Language="C#" CodeBehind="MASTER_PAGE_NAME.Master.cs" Inherits="PROJECT_NAME_Page1" %>
<asp:ContentPlaceHolder ID="head" runat="server">
</asp:ContentPlaceHolder>
<asp:ContentPlaceHolder ID="main" runat="server">
<div id="maindiv">
</div>
</asp:ContentPlaceHolder>
Last you need to create a content page for your masterpage by rightclicking your masterpage on solution explorer and click "Add Content Page"
<%@ Page Language="C#" AutoEventWireup="true" MasterPageFile="MASTER_PAGE_NAME.Master"
CodeBehind="Admin.aspx.cs" Inherits="PROJECT_NAME.CONTENT_PAGE_NAME" %> // the top of your content page will look like this.
// you will have this too on your content page
<asp:ContentPlaceHolder ID="head" runat="server">
//put 1 or more links from your masterpage that you think this page will use.
</asp:ContentPlaceHolder>
// and this one too
<asp:ContentPlaceHolder ID="main" runat="server">
//create a function here that this page will run.
</asp:ContentPlaceHolder>