Camera in Flash air

Camera in Flash air

How to get 2 camera along time? I have code:
var cam1:Camera = Camera.getCamera("0"); enter code here var cam2:Camera =
Camera.getCamera("1"); enter code here
var vid1:Video = new Video(); enter code here vid1.attachCamera(cam1);
enter code here mydiv1.addChild(vid1); enter code here
var vid2:Video = new Video(); enter code here vid2.attachCamera(cam2);
enter code here mydiv2.addChild(vid2);enter code here
But it only active 1 of 2 camera. Pls help me! Thank all.