On the side of your video on Youtube there are 2 links under your user name. One is URL, the other is Embed. Copy & paste the Embed link.
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/EiBfnGXkNBc&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/EiBfnGXkNBc&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>