link two table

[shalini166]

i have 2 table

maingroup(table 1)

fields:(mgshort name,mgcode,mgn ame)
values(EN,100,E ngine)


component(table 2)

fields:(mgshort name,component code,component name......etc.. .....)

values(EN,10,pa rtsname.......)

i used dropdownlist with items like (Engine,Deck,Pu mp Room etc);

when i select Engine from the dropdownlist1, then the component name should added into the dropdownlist2.

how to link two table.

pls help me any one who knows.