1. Open a spreadsheet window and right mouse click on the [Database Name] branch in the spreadsheet and select "Modify dataset properties".
or
2.Select "Modify Dataset Properties" from the File menu.
In the Modify Dataset Properties dialog select the database from the Dataset drop-down list and then choose a different field from the X Field and Y Fields drop down lists. Click Apply.
These default fields will not be changed immediately but only after the database is closed and then reloaded.