This has got to be possible! (personal search site engine)

heres wats going on. i am doing a site for a company, they have many products and i mean many. i want to build a search engine inside of the site. the thing is there are 5 sites to there company. i need the search to cover all 5 including all there products. using dreamweaver or flash how do i do this? i am using mx2004 as my programs. if this isnt clear about what i am asking then please say so, other wise let me know how to do this or where i can find info.

thank you everyone in advance on the help. have a good day-