I have a system that will be performing database queries, basic adding and 
editing that was originally for single user use. Now I want the system to 
be able to be used by concurrent users. (multi-users). Currently, the 
database is accessed by other pcs through a LAN (not a server). With this 
situation, how can I make it work for concurrent users, considering all 
the data integrity, for example, read-only, read and write, and if users 
are making changes at the same time. Thanks.