1) you must have this screen visible on your monitor
2) Click on Options button
3) Click on Upload Files button
4) Browse and select one file at a time from your personal computer.
5) Click on Open
6) Click on Upload button
7) Now you can see the file that you have just uploaded under file name title.
8) If the size of the file is too large, it may not be uploaded to the server. file size needs to be reasonable small (5 to 20 pages of a document is ok)