Possible Duplicate:
regex pattern to get Youtube ID from any Youtube URL
I would like to know how to trim a part of a URL like "http://www.youtube.com/watch?v=I4_3PVFSUxE&feature=plcp" and it will only output "I4_3PVFSUxE".
So I want to get the code that is after "v=" and delete whatever is after that.