Using variables across timelines help

I wonder how can I use this code for a nav to change over and out states.

This line of code works.

sym.getComposition().getStage().getSymbol("Section2").getSymbol("map_Popups").getSymbol("U SA").play("Over");

I try to save each country into a variable but doesn't work.

sym.setVariable("current2", "USA");

sym.getComposition().getStage().getSymbol("Section2").getSymbol("map_Popups").getSymbol(current2).play("Over");