Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
 
        Dim Prozess As String = TextBox1.Text
        Dim Vorhanden As Boolean
 
        For Each item As String In CheckedListBox1.Items
 
            If item.Contains(TextBox1.Text) Then
                Vorhanden = True
            Else
                Vorhanden = False
            End If
 
        Next
 
        If Vorhanden Then
            MsgBox("Der Prozess ist bereits in der Liste!", _
              MsgBoxStyle.Critical, "Fehler")
        Else
            CheckedListBox1.Items.Add(Prozess & ".exe")
        End If
 
        TextBox1.Clear()