Deleting related records in diffrerent tables

[H2_Oasis]

I have these three tables [ Orders, order_Items, order_comment ]\[code\]| -Orders- | | -Order_Items- | | -Order_comment- || order_id | | order_RegCode | | order_id || order_RegCode |\[/code\]As you can see, these three tables related together by 2 unique key! \[code\]order_id\[/code\] and \[code\]order_RegCode\[/code\].P.s: \[code\]order_RegCode\[/code\] is not Primary Key!i want when i delete any order by \[code\]order_id\[/code\], delete all related information that stored in two others tables. But when i using Do While i got \[code\]error Operation is not allowed when the object is closed\[/code\].please guide me.