I generally open the forms in the form's load event. Such as:

USE insured ALIAS insured ORDER TAG name IN 0
USE profiles ALIAS profiles ORDER TAG sysnum IN 0
SELE insured
SET RELATION TO insured.sysnum INTO profiles
GO TOP
DODEFAULT()

Then in the form's release (or unload) event I close all forms with something like:

DODEFAULT()
IF USED('customers')
USE IN customers
ENDIF

or

CLOSE TABLES

>In my old design, I put all the tables in the data environment.
>After 1 year, the form is loaded terribly slow .
>I found that the invoice's table size is over 20M and other around 6M
>Now, i need to remove all the tables and I don't know how to do .
>Some said i can open table as I need .
>However, I don't know How's the coding .(How can i open the table and close the tables?)
>Can anyone be kind to teach me ??
>Thx a lot