Automate reading or writing depending on the user

Good evening everyone,

does being not good in English I went through a translator

infact I have a workbook with a sheet that call "admin" with my username in column A password in column B and the name of my leaves C, D, E, F, I inserted a capital X on the line corresponding to the User column of the page to which I wish him given access if no X and hide this page
this is its gets complicated in fact I wish I could restrict access for some read-only user, and for others the total change.
you tell me add a password to the sheet but I would like this to be so kind to automate the user "Admin" to log in my userform it otez protect him because he will have total access to the reading workbook + modification.

if the user "Bernard" normally has access to the sheet 1 may continue to read my not change

I hope to have was clear in my description
thank you in advance for your assistance
if you had any questions do not hesitate I am behind the pc

here is my code currently used for identification in my file

    Private Sub UserForm_Initialize()
      Me.Utilisateur.List = Sheets("admin").Range("Utilisateur").Value
      Me.Utilisateur.ListIndex = 0
    End Sub
    Private Sub MotPasse_Change()
      p = Application.Match(Me.Utilisateur, Range("Utilisateur"), 0)
      mdp = Application.Index(Range("MotPasse"), p)
      If Not IsError(mdp) Then
        If Me.motpasse = CStr(mdp) Then ok = True
      End If
    End Sub
    Private Sub B_ok_Click()
      If Me.motpasse <> "" And Me.Utilisateur <> "" Then
         NbEssai = NbEssai + 1: Me.Label3.Caption = NbEssai & " essai(s)"
         For i = 1 To Range("MotPasse").Count
           If UCase(Me.motpasse) = UCase(Range("motpasse")(i)) And _
             UCase(Me.Utilisateur) = UCase(Range("utilisateur")(i)) Then
             For j = 1 To [feuille].Count
               If Range("droits").Cells(i, j) = "X" Then
                  temp = Range("feuille")(j)
                  Sheets(temp).Visible = True
               End If
             Next j
             Sheets("Espion").[M2] = Me.Utilisateur
             Unload Me: Exit Sub
           End If
          Next i
       End If
       If NbEssai > 3 Then
          MsgBox NbEssai & " essais!"
          ThisWorkbook.Close False
       End If
    End Sub

here is my page Admin
Capture.PNG

http://www.ozgrid.com/forum/showthread.php?t=89008