How to make a login form that gives access of two user on different levels.

See more:

VB

MS-Access

I'm developing a system in vbnet and access. I would like that my system gives access to 2 user with different levels of access, I would like that the first one as admin that access it own form called LibrarySystemForm as an administrator and the second one a User that access its own form too called cuulibForm.
Here the code I've used give them the to the same access, what should I do, to have another access to the second user that is different to the admin? ok I hope to get your advice
I would suggest someone who may advice me how I can change a bit on this following codes.

Imports System.Data.OleDb

Public Class LoginCuuLibForm
    Dim con As New OleDbConnection

    Private Sub LoginCuuLibForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        con.ConnectionString = "Provider= Microsoft.ACE.OLEDB.12.0;Data Source = CUULibDB.mdb.accdb; persist security info =false"
    End Sub

    Public Function ask()
        Dim dt As New DataTable
        Dim ds As New DataSet
        ds.Tables.Add(dt)
        con.Open()
        Dim da As New OleDbDataAdapter("Select * from login", con)
        da.Fill(dt)

        For Each datarow In dt.Rows

            If txtUsername.Text = datarow.item(1) And txtPassword.Text = datarow(2) And cobSertype.Text = datarow(3) Then
                con.Close()
                Return True


            End If

        Next
        con.Close()
        Return False

    End Function


    Private Sub btnLog_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLog.Click
        If ask() = True Then
            LibrarySystemForm.Show()
        Else
            MessageBox.Show("invalid")
        End If

       
    End Sub



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        txtUsername.Clear()
        txtPassword.Clear()
    End Sub
End Class