Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click
 // mencari user dari user dan password yang di inputkan
Dim a As New SqlCommand("select * from log_in where username = '" & UsernameTextBox.Text & "' and password = '" & PasswordTextBox.Text & "'", Module1.koneksi)

    //eksekusi query
        Dim dr As SqlDataReader = a.ExecuteReader
    //membaca table
        dr.Read()
    //membaca row dari table yang bersangkutan
        If dr.HasRows = True Then
        //jika item index ke 3 bernlai 2(item ke tiga apabila index dibaca dari ke 0)
            If dr.Item(2) = 2 Then
                MainMenu.Button1.Visible = False
                MainMenu.Button2.Visible = False
                MainMenu.Show()
                Me.Close()
        //jika item index ke  3 bernilai 1 (item ke tiga apabila index dibaca dari ke 0)
            ElseIf dr.Item(2) = 1 Then
                MainMenu.Button3.Visible = False
                MainMenu.Show()
                Me.Close()
            Else
                MainMenu.Show()
                Me.Close()
            End If
        Else
            MsgBox("username dan password tidak terdaftar")
        End If
    End Sub

    Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cancel.Click
        Me.Close()
    End Sub

    Private Sub LoginForm1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            Module1.koneksi.Close()
        Catch ex As Exception
            MsgBox("database setting error")
            Module1.koneksi.Close()
            DBset.Show()
            Me.Close()
        End Try
    End Sub