go to You are not allowed to view links.
Register or
Loginwww.youtube.com
click on any vid on their home page
when the vid comes up look in the address bar
you'll see something like You are not allowed to view links.
Register or
Loginyou want the bit after v=
that's the code that should go in between the youtube tags.
EDIT: just realized what I think you're doing wrong.
You're adding the bit after v= on this kind of link You are not allowed to view links.
Register or
LoginIn the case of ones like this you need the bit after v= and up to but not including the &
So in the one above you should end up with uh_81Ywan9Y