Hello :
You need to edit your link :
Here is Your's Link :
Remove Red Words From your link
http://www.youtube.com/watch?v=NJT_6sC2p3s
And After Removing Red words Do Flash :
and Your Final Link Will Be Like This
[center][flash=640,480]http://www.youtube.com/v/NJT_6sC2p3s[/flash][/center]
And change Flash video size
From
[flash=200,200]http://[/flash]
To
[flash=640,480][/flash]