Password Login To View Sheets

I have a workbook which, on opening, shows a logon form and depending on the username and password entered only certain sheets open - there are about 10 usernames and passwords - i have only included 2 to keep the code a bit shorter. I got the code below from here and it works perfectly but I want to make it a bit easier to add new usernames and passwords and am thinking of using a Vlookup table. The code i currently use is:

Option Explicit
Const sName1 As String = "Lisa"
Const sName2 As String = "Philip"
Const sPw1 As String = "update"

Dim sPW As String, sUser As String
Dim sMsg As String, sTitle As String, sStyle As String
Dim iCounta As Integer
Private Sub cmbValidate_Click()
sTitle = "Incorrect Password"...........