how to code a 3 times attempt log in

Imports MySql.Data.MySqlClient
Imports System.IO


Public Class frmlogin

    Private Sub btnexit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnexit.Click
        End
    End Sub

    Private Sub btnlogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnlogin.Click

        On Error GoTo err
        Dim conn As New MySqlConnection
        Dim areader As MySqlDataReader
        Dim cmd As New MySqlCommand

        Dim loginat As Integer = 0

        conn.ConnectionString = "Server = localhost; Database = data; User ID = root; Password = "
        cmd.Connection = conn
        conn.Open()


        cmd.CommandText = "select * from admin where username ='" & txtuser.Text & "'"
        cmd.Connection = conn
        areader = cmd.ExecuteReader()

        Dim validlogin As Boolean
        validlogin = False


        If areader.HasRows = True Then
            areader.Read()
            If areader.Item("password") = txtpass.Text Then
                validlogin = True


                Dim fn, position, user_type As String
                Dim image As String
                fn = areader.Item("FirstName")
                position = areader.Item("position")
                user_type = areader.Item("type")


                If txtuser.Text = "" And txtpass.Text = "" Then
                    MsgBox("Please fill in all boxes")

                ElseIf user_type = "Main Admin" Then

                    MsgBox("Welcome " & fn & " you login as Main Administrator ", MsgBoxStyle.Information, "Access Granted")

                    loginat = 0

                    frmadmain.Show()
                    Me.Hide()


                    frmadmain.lblname.Visible = True
                    frmadmain.lblname.Text = fn
                    frmadmain.txtUser.Text = user_type
                    txtuser.Text = ""
                    txtpass.Text = ""

                Else

                    MsgBox("Welcome " & fn & " you login as " & position & " ", MsgBoxStyle.Information, "Access Granted")

                    loginat = 0

                    frmmain.Show()
                    Me.Hide()

                    frmadmain.lblname.Visible = True
                    frmadmain.lblname.Text = fn
                    frmadmain.txtUser.Text = user_type
                    txtuser.Text = ""
                    txtpass.Text = ""


                End If


            Else
                txtuser.Text = ""
                txtpass.Text = ""
                txtuser.Focus()
                txtpass.Focus()
                MsgBox("Password not match", MsgBoxStyle.Exclamation, "Access Denied")
                loginat += 1

            End If
        Else
            txtuser.Text = ""
            txtpass.Text = ""
            txtuser.Focus()
            txtpass.Focus()
            MsgBox("Incorrect username", MsgBoxStyle.Exclamation, "Access Denied")
            loginat += 1

        End If

        lbllog.Text = loginat

        If loginat = 2 Then
            MsgBox("Last change to login, or the system will close!", MsgBoxStyle.Exclamation, "Caution")
        ElseIf loginat = 3 Then
            MsgBox("Sorry the system will now close!", MsgBoxStyle.Exclamation, "Caution")
            Me.Close()

        End If



        If validlogin = True Then

            Dim alreadylogin = True
            Dim userlogin = areader.Item("username")
            txtuser.Text = ""
            txtpass.Text = ""

            areader.Close()

            ' you can add another code or call function in this section
            ''Me.Dispose()

        Else
            areader.Close()
            txtpass.Text = ""
            MsgBox(Err, MsgBoxStyle.Information)

        End If





        Exit Sub
err:

    End Sub
End Class