This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Frames are a client side phenomenon. To the server, they're different webpages generated from different requests. You'll either need to store the value in a session scoped variable or use client side coding to pass the value between frames.