I have a form with three pages in a pageframe,

page1 use table1 (Primary Key pkey)
page2 use table2 (Regular Key pkey)
page3 use table3 (Regular Key pkey)
relationship table1 one-to-many table2, and one-to-many table3

I have start by;
use table1 in 0 shared
use table2 in 1 shared
use table3 in 2 shared

And at the form, I have add the three tables into the data environment.

How can I do to make all the three table append blank when I issue just one command? And where should I issue it?
I always have this problem that although the three tables are in a form, but they work alone by itself. When I skip 1, append, delete, it affect only one table. What should I do to have all the tables react to my commands?