update table from a form with macros(urgent)

[peter]

hi i need urgent help to know how to update a form
related to a table with a relation 1 to n to another
table.
in the form there is client id and end user id sometimes
the end user is the client by default. when entering new
contract number i have to get automaticly the phone
number adress... of the client and same for end user. so
i need macros or anything else to update the informations
in the tables related to the form , so that the update
will be registered in the tables.
thanks