1) Paste “thisXDocument.PrintOut()” under the code of Print button you placed.
2) Give full trust to your form and sign it.
3) Now publish the form either to sharepoint or localdirectory.
4) Open the published form and click that Print button .
5) A dialog will be displayed asking you to save that file with an extension “mdi”.
6) Click on save and you will see the print preview of that form.
7) You can now do whatever you want regarding printing.