embedded button in RoleGroup

 Hi,
The following is the .aspx code:
 <asp:loginview id="LoginArea" runat="server">
                <AnonymousTemplate>
                    <asp:login id="Login1" runat="server" >
                    </asp:login>
                </AnonymousTemplate>
                    <RoleGroups>
                        <asp:RoleGroup Roles="Merchant"& ...