Text Encrypter and Decrypter

Public Class Form1
    Dim coffset As Integer = 0
    Dim offsets As Array
    Dim intvector As Array = {1, 25, 50}
    Private Sub setintvector()
        coffset = 0
        offsets = TextBox3.Text.Split(",")
        intvector(0) = NumericUpDown3.Value
        intvector(1) = NumericUpDown2.Value
        intvector(2) = NumericUpDown1.Value
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        setintvector()
        TextBox2.Text = String.Empty
        For Each ii As Char In TextBox1.Text
            Dim ascval As UInt64 = (Asc(ii) + intvector(1))
            intvector(1) = intvector(1) + offsets(coffset)
            coffset = coffset + 1
            If coffset >= offsets.Length - 1 Then
                coffset = 0
            End If
            If intvector(1) > intvector(2) Then
                intvector(1) = intvector(0)
            End If
            TextBox2.Text = TextBox2.Text & ascval.ToString("X2") & "-"
        Next
        TextBox2.Text = TextBox2.Text.Remove(TextBox2.Text.Length - 1)
    End Sub

    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        setintvector()
        TextBox1.Text = String.Empty
        Try
            Dim enctext As String = TextBox2.Text.Replace("-", String.Empty)
            Dim bytes As New ArrayList
            While enctext = "" = False
                bytes.Add(Chr(("&H" & enctext.Substring(0, 2)) - intvector(1)))
                enctext = enctext.Remove(0, 2)
                intvector(1) = intvector(1) + offsets(coffset)
                coffset = coffset + 1
                If coffset >= offsets.Length - 1 Then
                    coffset = 0
                End If
                If intvector(1) > intvector(2) Then
                    intvector(1) = intvector(0)
                End If
            End While
            For Each item In bytes
                TextBox1.Text = TextBox1.Text & item
            Next
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub
End Class