CheddarBug
Welcome to Tek-Tips.
Duane has talked to you about database design.
But there are two things, partially addressed in the above posts for your thread.
First, is the creation / assignment of the primary key. A primary key is essential with a database design -- each record must be uniquely defined. A common approach is to use the AutoNumber data type. However, in a multi-user environment, use of AutoNumber is problematic. It is possible for two or more users "grab" the same AutoNumber field. The AutoNumber, if used, is assigned when a person starts entering a new record. This is called the OnInsert event. If several people are creating a record at about the same time, they could all grab the same AutoNumber. For example, imagine several data-entry clerks entering an Order, entering all the details for the order takes five minutes, so two or three clerks "grab" the same Order number. In theory, only one clerk will be able to enter the order and the other two will get an error when they try to update the record because the table will not allow a record with a duplicate AutoNumber -- breaks the rule for uniquely identifying each record.
See MichaelRed's FAQ on another apporach...
Why AutoNumber shouldn't be used in MultiUser databases (And How to ge the Unique Number)
Second, multiple users can edit the same record. Only the results of the last person who saves will ben seen -- they will over-write the data entry from the other users.
As a start, with multiple user database applications, set the options for all users openning the database....
From the menu, "Tools" -> "Options" and select the "Advanced" tab, and ...
Default Open mode: Shared
Default record locking: Edited record
Open database using record-level locking (enabled)
You may wonder why Access is causing you so much grief, and you may have expectations that Access should do a better job in handling multiple users -- I understand. However, Access is a relatively inexpensive yet pwoerful tool. Other more powerful databases that are better suited for multiuser access with better security will cost significantly more, and require more database administration.
Richard