Display pdf on the screen without saving from crystal report

I want to display pdf from crystal report viewer without save the file.

How to modify the code below so that it only display pdf file on the screen?

Dim CrExportOptions As ExportOptions
Dim CrDiskFileDestinationOptions As New DiskFileDestinationOptions()
Dim CrFormatTypeOptions As New PdfRtfWordFormatOptions()
CrDiskFileDestinationOptions.DiskFileName = "d:\crystalExport.pdf"
CrExportOptions = rpt.ExportOptions
With CrExportOptions
.ExportDestinationType = ExportDestinationType.DiskFile
.ExportFormatType = ExportFormatType.PortableDocFormat
.DestinationOptions = CrDiskFileDestinationOptions
.FormatOptions = CrFormatTypeOptions
End With
rpt.Export()