vers2

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Dim _NrOfTimes As String
        Dim _counter As Integer
        ListBox1.Items.Clear()

        Try
            _NrOfTimes = CInt(Val(TextBox1.Text))
            '_NrOfTimes = Convert.ToInt32("_string_nr") ' converting string to number
            If _NrOfTimes = 0 Then 'wrong input - empty or string
                MsgBox("Please enter a number")
            Else : getList(_NrOfTimes)
            End If
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

    End Sub
    Function getList(ByVal nr As Integer)
        Const a = 100, b = 200
        Dim _randomnum As Integer
        Dim _counter As Integer '??

        Randomize()

        For i = 1 To nr
            _randomnum = Int(Rnd() * (b - a + 1) + a)
            ListBox1.Items.Add(_randomnum & " - " & _counter)
        Next

        Return True
    End Function