Having trouble with youtube Embed videos
 

Right now I currently have set up a bbcode to help embed youtube videos. However, if the video someone tries to embed does not match the size of the one I used to set up the bbcode, then the video wont show and instead the one I used as an example in the BBcode ends up showing. Could someone please shed a little light on how I could fix this. I am new at using vbulletin and writing code in general, so any help is greatly appreciated.

Nick