AS1 How do i set up an array of classes?

heres my code for making one class
cwall = function () {
this.x = 0;
this.y = 0;
this.vwidth = 0;
this.vheight = 0;
};
_global.wall_A = new cwall();
what would i do to make _global.wall_A an array of classes?
also how would i call them?(i.e is it like _global.wall_A[2].x=5