command1_click()
use e:\eee\b1.dbf
browse
use
command2_click()
use e:\eee\b2.dbfbrowse
use
command3_click()use
select 0
use e:\eee\b1.dbf alias t1
select 0
use e:\eee\b2.dbf alias t2
select t1
go top
do while !eof()
    select t2
    locate for bill=t1.bill
    if found()
        select t1
        delete
    endif
    select t1
    skip
enddo
pack
use
use