I'm trying to make an instance of a class based on a variable name, like so:

var cn:String = 'Foo';
var c = new cn(); // i didn't think this would work...

Where c would create an instance of class Foo. I've also tried:

var c = new eval(cn)();
var c = new eval('cn')();

and then:
var cn:String = 'Foo()';
var c = new eval(cn);

I've done this in php, but can't seem to get this to fly in actionscript...

Any ideas? Thanks in advance!