C# - Access Items Inside A Telerik Menu Item?

I am trying to use this solution to access items inside a telerik menu item:

ascx code:

<asp:Label ID="DivLeave" runat="server"></asp:Label>

In the ascx.cs file I run this code to disable the asp label

RadMenuItem expenses = RadMenu1.FindItemByText("Expenses");
Label DivLeave = (Label)expenses.FindControl("DivLeave");
DivLeave.Visible = false;

but I get this error when I try to run the code:

{"Object reference not set to an instance of an object."}

I really need to run this server side as code surrounding the above code does some work server side and it will all fit in neatly...