ActionScript 3.0 :: Declaring Dynamic Vars Locally?

Although I have a long experience with AS2, I am just stepping in AS3 now. As should be expected, I have bumped a few issues here and there, that really puzzles me.

One of them is the way to correctly name a variable dynamically. In AS2, as far as I know the only way to do that is with _root, like that:

Code:
for (var z=0;z<=5;z++)
_root["myvar"+z] = z;

I have used quite the same way to do that in AS3, like that:

Code:
for (var z=0;z<=5;z++)
root["myvar"+z] = z;

However, it doesnt seem to be too good, because it just allows me to create global variables. What if I want to create local vars into the function? I tried to remove the "root" and use "var" statement but ActionScript doesnt like that (it tells me that there is an identifier missing before the left bracket):

Code:
for (var z=0;z<=5;z++)
var ["myvar"+z]:Number = z; // Flash yelds when I try that!

What is the trick to do that... or simply THERE IS NOT a way to do that, but always declare dynamic vars as public??