Generate random textboxes to show random numbers

I'm trying to create a program which selects textboxes from the list at random and generate random numbers from 1 to 5 in those textboxes, but with no success. I have 10 textboxes named Textbox1- Textbox10, 1 textbox named TxB1 and 1 button. In TxB1 user should specify number of selected at random textboxes. For example: user has specified number 4 in TxB1, has clicked button1 and then numbers from 1 to 5 should appear in 4 different textboxes choosed at random. Here is the code I tried with no luck...

    Dim rn As New Random 
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
            Dim RandomNumberAHigh2 As Integer = 4
            Dim RandomNumberALow2 As Integer = 1
            Dim index2 As Integer = rn.Next(1, TxB1.Text)
            Dim MyListOfTextBoxes() As TextBox = {TextBox1, TextBox2, TextBox3, TextBox4, TextBox5, TextBox6, TextBox7, TextBox8, TextBox9, TextBox10}
            For index = 0 To 9
                Dim RandomNumberAHigh As Integer = 12
                Dim RandomNumberALow As Integer = 1
                Dim Random As Integer = 0

                For i As Integer = 0 To index2
                    MyListOfTextBoxes(index2).Text = Int((RandomNumberAHigh - RandomNumberALow + 1) * Rnd() + RandomNumberALow)
                Next
            Next
        End Sub