How to dynamically load different classes?

programming flash
1

I want to do something like this:

eval("var "+ class_iname +" = new"+class_name+"();");

But since this is not possible, how would I dynamically load different classes?

Should I use the loader class?
This example does, but it requires pre compiling of the class in question + I am using AIR.: http://wahlers.com.br/claus/blog/as3-loading-class-libraries-at-runtime/

What are the alternatives?

Thanks for youe help.