Auto Complete Search Box

Hello All,

I have a website that has city pages(plugin i created based on groups plugin)...there are 2 things i would like to do:

1.  Auto complete the search box with city names.

2.  If a blog post contains a city name..i would like to create a link to the city page..

I am not sure how autocomplete works..i mean where does it look for the words(to compare) file. If needed, i could create that file by hand..but ideal would be if it is created from database.

For part 2, if someone could recommend a Jquery plugin..it would be great.

Thanks

Appreciate all the help!