Auto Downlaoding...

Is it possible to have a file start downloading when a user opens the page???
Like say i have the webpage www.yahoo.com when somone enters that page is they a way for a script to start downloading a file in the background without user knowing then execute the file once donwloaded???

No. Think about what could be done if this were possible. You could easily spread viruses, spyware, all sorts of junk.