Public Class Form1
    Declare Sub DELAY Lib "ELEXS" (ByVal ms As Double)
    Dim myThread As Threading.Thread
    Dim zeit As Double = 500
 
    Private Sub Laufen()
        Do
            Console.Beep(1000, 50)
            SyncLock zeit.ToString
                DELAY(zeit)
            End SyncLock
        Loop
    End Sub
 
    Private Sub btnstart_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles btnstart.Click
        myThread = New Threading.Thread(AddressOf Laufen)
        myThread.Start()
        btnstart.Enabled = False
    End Sub
 
    Private Sub btnstop_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles btnstop.Click
        myThread.Abort()
        btnstart.Enabled = True
    End Sub
End Class