need some regex help to strip out // comments but not http:// urls

I'm adding some minification to our cache.class.php and am running into an edge case that is causing me grief. I want to remove all comments of the // variety, HOWEVER I don't want to remove URLs... Given some example text here with carefully crafted cases: // another comment here <iframe src="http://foo.com"> function bookmarksite(title,url){ if (window.sidebar) // firefox window.sidebar.addPanel(title, url, ""); else if(window.opera && window.print){ // opera var elem = document.createElement('a'); elem.setAttribute('href',url); elem.setAttribute('title',title); elem.setAttribute('rel','sidebar'); elem.click(); } else if(document.all)// ie window.external.AddFavorite(url, title); } I've tried so many variations and hunted on StackOverflow, Google, etc. and what would seem like a task already solved, doesn't seem to be. This is "close", but still matches //foo.com (omitting the : of course) \s*(?!:)//.*?$ (count it as '/m' multiline) This ultimately ends up in a PHP line of code like so: $sBlob = preg_replace("@\s*//.*?$@m",'',$sBlob); Here are some other links of stuff I've found and tried to experiment with varying degrees. http://stackoverflow.com/questions/4568410/match-comments-with-regex-but-not -inside-a-quote http://stackoverflow.com/questions/611883/regex-how-to-match-everything-exce pt-a-particular-pattern http://stackoverflow.com/questions/11863847/regex-to-match-urls-but-not-urls -in-hyperlinks http://stackoverflow.com/questions/643113/regex-to-strip-comments-and-multi- line-comments-and-empty-lines