System.NullReferenceException: Object reference not set to an instance of an object. - Trying to hide button in details view

I have a detils view on a page, that if a user isn't a "PowerUser", I need to hide the edit button of the detailsview.   But, I keep getting this error.  Object reference not set to an instance of an object.
Here's my code from my code behind, where I'm checking the access level, and if  the user isn't the proper level, I'm trying to hide the button.  What am I forgeting to do? 

From my page  & Code behind
<asp:TemplateField HeaderText=""> <EditItemTemplate> <asp:Button ID="btnUpdate" runat="server" CausesValidation="True" CommandName="Update" Text="Update" /> <asp:Button ID="btnCancel" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel" /> </EditItemTemplate> <ItemTemplate> <asp:Button ID="btnEdit" runat="server" CausesValidation="False" CommandName="Edit"Text="Edit"/> </ItemTemplate> &l ...