Public Class Form1

    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        Label1.Text = Convert.ToString(TextBox1.TextLength)
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        TextBox2.Clear()
        If (TextBox1.TextLength Mod 2) = 0 Then
            Dim txtNoSplit() As Char = TextBox1.Text.ToCharArray()
            For i As Integer = 0 To TextBox1.TextLength / 2
                TextBox2.Text += txtNoSplit(i)
            Next
        End If
    End Sub
End Class