Login feature, help on adapting it for multiple users

Hi All

Can anyone help me? I have gone brain dead. What i am trying to achieve is a user security login feature that alows certain access to certian people.
At the moment the access levels assigned changes the colour of a cell (as i will add more code later). But what i am really stuck on is adapting it for multiple users, ie me (James) and Lara. I just cannot remeber the Vba to do it.

Heres the code so far:

Sub workbook_open()
UserName = InputBox("Please Enter Your Login ID", "Login In")
If UserName <> "Lara" Then GoTo Wrongname
Range("B4").Select
With Selection.Interior
.ColorIndex = 6
.Pattern = xlSolid
End With
Range("B6").Select
Exit Sub
Wrongname:
MsgBox "You can only access this document as view only"
Range("B4").Select
Selection.Interior.ColorIndex = 3
Range("B6").Select
Exit Sub
End Sub


Any help will be much appriciated

Thanks

Thanks very much Mallycat