I shot video of someone in front of a green screen. I want to key out the green and replace it with a more interesting background. I've followed the basic instructions in Vegas help (there's not a lot there, really) but it isn't workng right.

Can anyone answer the following questions for me?

Should my video of the person in front of the green screen go on the highest track? Is it a parent track?

Does the background I want to replace it with go on the lower track? Is it a child?

Am I missing something here?

Thanks in advance...

JG