How to Make an Advanced Auto Typer in Visual Basic 2008/2010

How to Make an Advanced Auto Typer in Visual Basic 2008/2010
~
Requirements:
1 Timer
2 Buttons (Button1 ~ Start) (Button2 ~ Stop)
2 Textbox (Textbox1 ~ Multi-line) (Textbox2 Text ~ 1 )

Timer1:
SendKeys.Send(TextBox1.Text)
        SendKeys.Send("{Enter}")

Button1 ~ Start
Try
            If TextBox2.Text = "" Then MessageBox.Show("Choose a speed", "Information")
            Timer1.Interval = TextBox2.Text * 1000
            Timer1.Start()
        Catch ex As Exception
            MessageBox.Show("Invalid number, choose a valid speed", "Information")
        End Try

Button2 ~ Stop
Timer1.Stop()

-- DEBUG --