I have the same problem.
We are integrating FileMaker 13 database into a website, which has user control. We need to see how a user account info can be passed into FM webdirect through URL or posting, so that the user doesn't need to login to FM again !!
Based on the following page posted on July 2014
That page mentioned :
“The capability to specify URL parameters or to bookmark specific locations within FileMaker WebDirect solutions has been removed for security reasons. You now specify only a filename in the URL to open that file.
We need to see a solution on how to pass the user account info into FM webdirect. And nice to see a session control ability built in FM webdirect as well.
Please keep me posted if you know an answer.