[2005] How do you stop a Marquee from going?

[Giraffe Frenzy]

Below is my code. I need the app to run as long as listbox1 is being populated with data (i can't figure this part out).

ThreadPool = button
ProgressIndicator = progressbar
Listbox1 = listbox

Imports System.Threading

Public Class MainForm

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load, MyBase.Load, MyBase.Load, MyBase.Load
        ThreadID.Text &= CStr(Thread.CurrentThread.ManagedThreadId)
    End Sub

    Private Sub theLongRunningTask()
        Do While ListBox1.Items.Count < 50
            ProgressIndicator.Style = ProgressBarStyle.Marquee
            ListBox1.Items.Add("test")
        Loop
        ProgressIndicator.Style = ProgressBarStyle.Blocks
        ProgressIndicator.Value = 0
    End Sub

    Delegate Sub TaskDelegate()

    Private Sub ThreadPool_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ThreadPool.Click
        Dim td As New TaskDelegate(AddressOf theLongRunningTask)
        td.BeginInvoke(Nothing, Nothing)
    End Sub
End Class