>Any information about how I can control my application to run
>for specific users for example no more than 5 users.
>thank you in advance.

Have 5 dbfs, user1.dbf... or something a little more sneaky if you like, try to open the 1st one exclusive, if that doesn't works, try the second... all the way untill you hit the end. In order to be more secure (so users don't add more liscences by adding more files) scan through a 1 column table. Each Liscence will have a record pointing to the appropriate file. Use that to epn your files.