Use the Foreign Key Name edit box to enter a name for the new key and then select a table field to include in the key from the Field Names group.

Use the Reference Schema and Reference Table dropdown lists to select a foreign schema and table respectively.

To include field(s) to the key, just simply double-click the Field Names/Foreign Field Names field or click to open the editor(s) for editing.

Select the field(s) from the list. To remove the fields from the foreign key, uncheck them in the same way. You can also use the arrow buttons to change the foreign key field(s) order.