I found this website with google but those solutions are not 100% perfect, not in all browsers at least
I dont know how to use akshits code but it's not really working for me....
thedavinci's code (lol sounds funny :P) works but only in firefox.
I have come up with another solution which does not delete the code but makes it invisible. It does that by putting it into a 0px by 0px div and throw it into a corner behind your website. Here's the code:
<div style="font-size:0px; position:absolute; width:0px; height:0px; color:#000000; z-index:-1; overflow:hidden;"><xmp></body></xmp></div>