downloading from database

Hey everyone, I have a question about downloading from a mySQL database, running php on Apache. Basically right now I'm working on this file upload download tool. You login, see a list of files, (upload functionality works great). You click on a file name which pops up the new file in a new browser window. This new page contains a "download" button under where it displays the file(image, swf, pdf, etc). What I want to happen is that when I click on the download button I want the file to download to my machine. Instead right now, it just downloads the page that the button is on. Any ideas? Thanks in advance. Adil.