Walt,
Unfortunately, if the strangle is appplied correctly there is no escape. What you have to do is prevent the attack in the first place.
1. Avoid situations that could develop into conflict.
2. Don't let the guy get behind you.
3. If he does get behind you use balance and body position to prevent him from applying the choke. Then use whatever tools you have in your arsenal to get out of it.
No one here can teach self defense over the Net, you need to take these questions to a qualified instructor and take the time to learn the techniques.
Finally, remember that there is no 'magic' solution, if you get into a fight be accept that you may lose.
Regards
Neil
Neil Hawkins
"The one thing that must be learnt but
cannot be taught is understanding"