Visual Basic

Dim waitTime As Integer
Dim handle As New System.Threading.AutoResetEvent(False)

Sub Main()
    Dim rand As New System.Random
    waitTime = rand.Next(10, 20)
    Dim bw As New System.ComponentModel.BackgroundWorker
    AddHandler bw.DoWork, AddressOf WorkerRoutine

    Console.WriteLine("Wait time will be {0} seconds", waitTime)
    bw.RunWorkerAsync()
    'Console.WriteLine("Press any key to interrupt the worker.")
    'Console.ReadKey()
    'handle.Set()
     
    Console.WriteLine("Program complete...")
    Console.ReadKey()
End Sub

Private Sub WorkerRoutine(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs)
    Console.WriteLine("Beginning work")
    System.Threading.Thread.Sleep(waitTime * 1000)  'gives a non-interruptable sleep
    'handle.WaitOne(waitTime * 1000, False)   'gives an interruptable "sleep" period
    Console.WriteLine("Ending work")
End Sub