Hiding variables in PHP

hello,
I have a question about varibles in PHP. I have a flash project I am working on and want it available for viewing online, but don’t want it to be downloadable because it may be tampered with. What I was wondering is if there is a way to assign the variable the name such as flash = “mymovie.swf” and making it so that mymovie.swf is shown in the broswer window, but the actual name mymovie.swf doesn’t appear in the HTML page source. If somebody could help me out with this, or recomend another method for me to use, that would be very appreciated!
thanx