Fellow speaker,
If your mind goes blank onstage, keep calm. KEEP QUIET until you remember what you are going to stay. Stay calm, look from person to person in the audience, review in your head where you were in your speech, think about what logically comes next...and eventually you will pick up the "thread" of your speech again. It takes a little while, but all you have to do is...wait it out!
Waiting it out,
Tim
