How can I link 4 sub-forms in one main form

[tina]

my guess is that your main report is unbound, and the 4
sub-reports (not sub-forms) are each bound to a parameter
query. you can add a query or select statement to your
main report's record source, with a parameter for the
dossier number. then you can link the sub-reports to the
main report, and change the sub-report queries from
parameter queries to simple select queries.
hth