As you have been told that no one in this world can levitate all you see is just illusion, each person who have seen Criss Angel levitating is just an art of trick

SECRET

it is all pre-arranged by Cirss Angel,, what you dont know is that his pents are prepared for levitations,, when he faces back the spectators he uses some misdirection just to take his one leg out from pent and plant it on any thing that is little bit high for example(side walk or chair something).

When he is done doing this dirty work,, he just lifts him self on one leg,, people see that his both feet are up in the air,, because when he takes out one leg his pents remain in both leg shape giving the view that both feet or same.

The levitation in which he is facing camera is just camera editing and the spectators are his on crew.