is it possible to edit the list of roles displaying?

Hi everyone 
On Step 2 of my 'Create User' Wizard I have a listbox of 4 roles displayed, this allows a superUser to choose a role for the user being created. 
However I only need to display 3 of the 4 roles, e.g. I don't need further superUser's creating.  So only being shown the 3 remiaing roles reduces the amount of superUser I now have.
Here's my code, if it helps...
' Activate event fires when the user hits "next" in the CreateUserWizard Public Sub AssignUserToRoles_Activate(ByVal sender As Object, ByVal e As EventArgs) ' Databind list of roles in the role manager system to a listbox in the wizard AvailableRoles.DataSource = Roles.GetAllRoles() AvailableRoles.DataBind() ' Save the profile - must be done since we explicitly created this profile instance End Sub ' Deactivate event fires when user hits "next" in th ...