How to get save dialog box to save the generated pdf

private void BtnSave_Click(object sender, EventArgs e)
{
    if (this.pdfDocumentViewer1.PageCount > 0)
    {
        SaveFileDialog dialog = new SaveFileDialog();
        dialog.Filter = "PDF document (*.pdf)|*.pdf";
        DialogResult result = dialog.ShowDialog();
        string fileName = dialog.FileName;
        if (result == DialogResult.OK)
        {
            pdfDocumentViewer1.SaveToFile(fileName);
            MessageBox.Show("You have saved this PdfDocuemnt as:\n" + fileName, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    }
}
private void BtnSaveStream_Click(object sender, EventArgs e)
{
    if (this.pdfDocumentViewer1.PageCount > 0)
    {
        SaveFileDialog dialog = new SaveFileDialog();
        dialog.Filter = "PDF document (*.pdf)|*.pdf";
        DialogResult result = dialog.ShowDialog();
        string fileName = dialog.FileName;
        if (result == DialogResult.OK)
        {
            MemoryStream stream = new MemoryStream();
            pdfDocumentViewer1.SaveToFile(stream);
            byte[] fileBytes = stream.ToArray();
            FileStream fileStream = new FileStream(fileName, FileMode.Create, FileAccess.ReadWrite);
            fileStream.Write(fileBytes, 0, fileBytes.Length);
            fileStream.Flush();
            fileStream.Close();
            stream.Close();
            MessageBox.Show("You have first saved this PDF docuemnt as memory stream,\nthen write the memory stream in a file :\n" + fileName, "Spire.PdfViewer Demo", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    }
}
}