Imports System.Data.OleDb
Module Module1

    Public admin As Boolean  'Use to identify if current user is Administrator

End Module

Public Class StaffLogin

    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        username.Clear()
        password.Clear()

    End Sub
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim cn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;" & "Data Source=C:\Users\In The Know\Documents\Database1.mdb")
        Dim cmd As OleDbCommand = New OleDbCommand("SELECT Username FROM StaffLogin WHERE Username = '" & username.Text & "' AND Password = '" & password.Text & "' ", cn)

        cn.Open()
        Dim dr As OleDbDataReader = cmd.ExecuteReader()
        If (dr.Read() = True) Then
            admin = dr("isManager")
            If (admin = True) Then
                MsgBox("Login Successful, " & username.Text & "!")
            Else
                MsgBox("you are not manager!")
            End If
        Else
            MsgBox("invalid login")
        End If
        cn.Close()

    End Sub
End Class

' Assumes that connection is a valid SqlConnection object.
Dim queryString As String = _
  "SELECT CustomerID, CompanyName FROM dbo.Customers"
Dim adapter As SqlDataAdapter = New SqlDataAdapter( _
  queryString, connection)

Dim customers As DataSet = New DataSet
adapter.Fill(customers, "Customers")