Disable Insert/Delete Worksheet

I can help with disallow a user to insert a new sheet but I am not smart enough to come up with a solution for disallow a user to delete a worksheet... Sorry.

Private Sub Workbook_NewSheet(ByVal Sh As Object) 
    With Application 
        .DisplayAlerts = False 
        .ScreenUpdating = False 
    End With 
    Sh.Delete 
    With Application 
        .DisplayAlerts = True 
        .ScreenUpdating = True 
    End With 
End Sub