2 патока 1 листбокс

Imports System.Threading
Public Class Form1
    Dim WithEvents cl As New Class1
    Dim theard1 As New Threading.Thread(AddressOf cl.cikl)
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        theard1.Start()
    End Sub
    Sub add_list(ByVal n As String)
        ListBox1.Items.Add(n)
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AddHandler cl.event1, AddressOf add_list
    End Sub
End Class

Public Class Class1
    Public Event event1(ByVal maks_number As String)
    Public Sub cikl()
        For maks_number = 1 To 10000
            If maks_number = 10000 Then
                RaiseEvent event1(maks_number)
            End If
        Next
    End Sub

End Class