This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
If you want to open the form in a new window, use window.open and load the JSP with search page. If you want to be all Web 2.0 about it, you can create a positioned div with a high z-index to float it above the page and either have it pre-loaded with the search form, or grab it from the server using Ajax.