Hello,
Please do not ask questions in full caps lock, you're less likely to get a reply and it will annoy a lot of people :)
You also did not explain what you had done to find the answer yourself, or what you had tried so far, which again will result in people being less likely to respond. In order to get a good answer from the community, you need to show you've done your homework.
For some great tips on how to get your post noticed in the future, please refer to;
In ref to your original question, read up on these;
Although I haven't used the channel variables approach, the docs suggest this will stop the A leg from being processed at all. The other option would be to ignore it in post processing.
If you are still stuck after reading through those, please reply back and tell us what you have tried, and where you are getting stuck.
Hope this helps