Hide Unorder List from code behind using C# in ASP.Net

Hello Forum, 

I already have a C# that hides button control when user is not an admin. I also want to make a list item on the navigation bar to be invisible when user who is not an admin logs in.

But when I used this it did not work

HTML:

<li class="dropdown">
    <a href="#" class="dropdown-toggle" data-toggle="dropdown"><asp:Label ID="user" runat="server" Font-Size="smaller" Text="" ForeColor="White"></asp:Label><img alt="" src="images/img1.jpg" height="20" /><b class="caret"></b></a>
    <ul class="dropdown-menu" id="dashboard" style="background-color: #00003D;">
        <li class="dropdown-header" id="dashB"><a href="DashBoard.aspx" style="color: #FFFFFF; font-size: small; background-color: #00003D;"> Panel</a></li>
    </ul>
</li>

C#

    public void showdata2()
    {
        cmd.CommandText = "select * from Users where email= '" + Session["user"] + "'";
        cmd.Connection = con;
        sda.SelectCommand = cmd;
        sda.Fill(ds, "detail");
        if (ds.Tables[0].Rows.Count > 0)
        {
            string UserRole;
            UserRole = ds.Tables[0].Rows[0][4].ToString().Trim().ToUpper();

            if (UserRole == "U")
            {
                lipaybutton.Visible = false;
                dashboard.Visible = false;
            }
            else if (UserRole == "A")
            {
                lipaybutton.Visible = true;
                dashboard.Visible = true;
            }
        }
    }