How to dynamically set the export path?

Question

Hello,

I am using ExportToDisk() method to save my crystal report in the pdf format.
Refer below:
[CODE]
MyReport.ExportToDisk(ExportFormatType.PortableDocFormat,"C:\MyReport");[/CODE] // Here the file is successfully saved to my C Drive with title as My Report.

However, my question is how to set the export path dynamically? ie. How to save the path (here C:\) Dynamically? ie...Like prompt a user to select the location where he wants to save the file? How can this be done?
I am using this work around because ExportToHttpResponse does not seem to work...please help.

Please help....