Integrated Virus Scanning

All,

I have an intranet application in ASP. In one of the modules it allows MS Office and PDF files to upload files to a file server. I need to add a virus checking component to it something like Yahoo/Hotmail does when we add an attachment.

I tried looking for API's of scanner such as Norton, Symantec,etc but could'nt find anything. One way i could think of was to use any commandline scanner, Scan the file in a command shell and send the results to a text file and read those results. But does'nt seems like a good option.

Can anybody guide me the best way to do.

Tks