I have built a monster...

On the maintime line I have a movie clip "map_mc" inside it I declare a variable "index_a" and have a series of buttons that populate that variable. This is working fine.

In "map_mc" I also have a movie clip "allstates" and inside that I have another movieclip "onestate" in this movieclip I have a series of buttons that I also need to update the variable in the root movie clip "map_mc" as above.

I have tried;
on (release) {
_root.map_mc.index_a="value";
}

But when I run a trace I get undefined, sure hope someone can straigten this out for me, I have a problem when it comes to scope issues.