<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true"
    CodeFile="Default.aspx.cs" Inherits="_Default" EnableViewStateMac="false" ViewStateEncryptionMode="Never" %>
                     ...
<asp:Content ID="Content1" ContentPlaceHolderID="MainContentPlaceHolder" runat="Server">
   <asp:Literal ID="gaScript" Visible="true" runat="server"></asp:Literal>
    <table border="0" cellspacing="0" cellpadding="0">
                     ...
</Content>

 if (!IsPostBack)
        {
           gaScript.Text = "bla-bla-bla";
         }