asp:Menu in master page pushes the content below on hover
**<div class="title">
     <h1>
     My ASP.NET Application
     </h1>
     </div>
<div class="clear hideSkiplink">
    <asp:Menu ID="mnuMain" runat="server" BackColor="#FFFFCC" CssClass="menu">
        <DynamicItemTemplate>
                  <%# Eval("Text") %>
        </DynamicItemTemplate>
    </asp:Menu>
</div>
<div class="main">
    <asp:ContentPlaceHolder ID="MainContent" runat="server"/>
</div>
<div class="footer">

   </div>**

**MenuItem item = new MenuItem();
    MenuItem item1 = new MenuItem();
    item.Text = "Main Menu";
    item1.Text = "sub menu1";
    item.ChildItems.Add(item1);
    mnuMain.Items.Add(item);**