Command button in a form

I have the following command button with an event procedure on click to
select all issuers by checking a check box:

private sub cmdselectall issuers click()
s = "Update [tbl Master comps] set [tbl Master comps].[issuer select check
box] = True"
"where [tbl master comps]. [issuer slecet check bo] = false"
currentdb.execute s
me.refresh
end sub

This command button is in a form that has a filter on it. It currently
selects all check boxes for all issuers and I want it to only check the check
box for issuers that are in the filter.

Any ideas on how to do that?

Thanks in advance