A database can be opened by one and only one user.
That user can share the file within Filemaker. Up to 9 users can access the shared file.
This is Filemaker's help page on filesharing.
Basically... after you open the file with the first copy of Filemaker Pro...
Open the file using File > Open Remote instead of opening the file directly.
You will then be able to browse for the IP address and should see the database file listed in the right hand window pane.
To make life easier, you may want to create a shortcut which points to : fmp7://ipaddress/filename
for example : fmp7://192.168.1.1/database
Thank you for this help page!!
Thank you for the simple to follow instructions! We are in business!