step1: add: "[@flash]" "[@/flash]" (remove all "" and @ when you are doing your thing )
step2: add the URL into the space between "[@flash]" "[@/flash]"
i.e. "[@flash]"http://www.youtube.com/watch?v=yHxn8mTpAJU"[@/flash]"
note: do not leave any space AND remove the "" and @ thing
step3: in the URL you added, noted the part: ../watch?v=....
change it to /watch/v/....
i.e. the original URL: http://www.youtube.com/watch?v=yHxn8mTpAJU
be modified to : http://www.youtube.com/watch/v/yHxn8mTpAJU