"I have this dilema. I have two a97 databases on two different locations. The databases are used to enter client transactions. How do I sync the database so that both databases will contain the same set of data (one database will get the new transactions entered from the other database and vice versa). The connection between the two computers can be done using a modem to modem connection at least once a day."
It sounds like you need to merge all of the data into one file, and then use Access replication to create the master and 1 replica (after which synchronization is a built-in feature). If you need to track the source of the data, you can add a field to both sides before the merge.
If you have autonumber PK's you have a lot to do. In the first file, for each table that has an auto PK, add a Long field, then update the new field to the value of the PK + a number higher than the highest corresponding PK in the other file.
If you don't have autonumber PK's, you still need to verify that there are no PK duplicates between the two. You can attach all of one's tables to the other, and run Find Duplicates queries on each pair of tables.
To perform the merge, start with the tables attached from one to the other. Do an append query for each pair of corresponding tables. Exception: If you had to re-number the PK's, you'll append your new PK field to the existing auto PK field.