The Tables list box should be populated with the tables created in the database by the table qualifier. You can select a table in the database by clicking on it with your mouse pointer.
You can also choose to specify a level 1 name in the Structure Name field as well as a field name prefix to be used in each level 2 name in the structure. For example, if you specify MYSTRUCT as the field name prefix, the level 2 names are MYSTRUCT001, MYSTRUCT002, and so on.
Click on the Generate Include Structure for Table button to continue.