<iframe width="560" height="315" src="http://www.youtube.com/embed/s4TmKodpqx8" frameborder="0" allowfullscreen></iframe>


The below code is for the embedded file above. The only difference is that I have moved the first < left by one space and the final > right by one space. This is just so you can see what the code looks like.

< iframe width="560" height="315" src="http://www.youtube.com/embed/s4TmKodpqx8" frameborder="0" allowfullscreen></iframe >