Add a dropdown search box to a Form page

[BKF]

I have a dbase with one table. I would like to add a search box to my Form page
that will pull a customers name from my "Account Name" field in my table and
show the person assigned to that customer; this is in my "Assigned To" field
in my table.

I would expect my dropdown list to look something like this:

ABC Corp. - John Smith
Help Me Inc - Bary Blue
etc..etc..

Thanks