ActionScript 3.0 :: Variable Storing Whether The Player Is Selected To Be Passed Back To The Actual Grid Class

I'm trying to make a game that is turn-based and allows players to first be selected, then click on a grid square to move there. However, I can't get a way for a variable storing whether the player is selected to be passed back to the actual grid class. I want the grid class to have an event listener that when the grid is clicked on, it will move the player there only if the player is selected. But whenever I try to declare a global variable either inside the grid class or even a document class or even access properties of the character class I'm trying to move I get errors.