How do I rank search results?

eg.
Search for "apple orange mango"


Result
100% - apple orange mango pineapple durian watermelon
67% - apple orange pineapple durian watermelon
33% - apple pineapple durian watermelon

how can i do this in ASP search with SQL server 2000?

thank in advanced

i would probaly build a stored procedure in sql. i am not sure of the best way, but maybe split the search string and then run three search queries, and add the return value together to build your rank...idk