vb.net image slicer

Public Class Form1
    Dim bitmap1 As Bitmap
    Dim outputPath As String = Nothing
    Private Sub btnInput_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnInput.Click
        Try
            OpenFileDialog1.ShowDialog()
            Label2.Visible = False
            Label2.Text = Nothing
            Dim fs As IO.FileStream = New IO.FileStream(OpenFileDialog1.FileName, IO.FileMode.Open)
            bitmap1 = Image.FromStream(fs)
            fs.Close()
            PictureBox1.Image = bitmap1
        Catch ex As Exception
            MsgBox("select an input path picture file")
        End Try
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        OpenFileDialog1.FileName = Nothing
        OpenFileDialog2.FileName = Nothing
    End Sub

    Private Sub btnOutput_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOutput.Click
        Try
            OpenFileDialog2.ShowDialog()
            outputPath = OpenFileDialog2.FileName
            outputPath = outputPath.Substring(0, outputPath.LastIndexOf("\") + 1)
            Label1.Text = outputPath
            Dim bmts As New Bitmap(bitmap1.Width \ 11, bitmap1.Height \ 11)
            For i = 1 To 11
                For j = 1 To 11
                    For hj = 1 To bitmap1.Height \ 11 - 1 ' y of now picture
                        For wi = 1 To bitmap1.Width \ 11 - 1 ' x of now picture
                            bmts.SetPixel(wi, hj, bitmap1.GetPixel(wi + (j - 1) * (bitmap1.Width \ 11), hj + (i - 1) * (bitmap1.Height \ 11))) 'fix
                        Next
                    Next
                    Dim bitmapToSave As New Bitmap(bmts)
                    bitmapToSave.Save(outputPath & (11 * (j - 1) + i) & ".bmp", Imaging.ImageFormat.Bmp)
                Next
            Next
            Label2.Text = "image slicing completed"
            Label2.Visible = True
        Catch ex As Exception
            MsgBox("have you selected an input picture ? is it standard size ?, have you selected a file in a output directory with no files named 1 - 121.bmp")
        End Try
    End Sub
End Class