The Joins dialog box shows the current table joins, allowing you to remove joins and change the join type.
To remove a join, click on the desired join and click Remove.
To change the join type, click on the desired join, click the arrow to the right of the Join Type list box, and select a join operator from the list that appears. You can select any of the following join type operators:
Outer Join (does not appear if more than one join is selected)
You can also change the join type by double-clicking the arrow representing the join on the Join Tables screen (see Joining Tables) and selecting a join type in the Configure Join dialog box that appears.