this.equals = function(other){

    var toReturn = other !== null;

    for (var r = 0; r < 3 && toReturn; r++) {
        for (var c = 0; c < 3 && toReturn; c++) {

            //Debug//
            document.write(tiles[r][c]); //Works, Prints 2 (correct)
            document.write(other.tiles[r][c]); //Does not, prints nothing
            //-----//

            if(tiles[r][c] !== other.tiles[r][c]) toReturn = false; //Not working, exits function
        }
    }
    return toReturn;
};

function assert(expression) {
            var result = eval(expression);
            if (!result) alert("Assertion failed: " + expression);
        }

        var start = new PuzzleState([[2, 8, 3], [1, 6, 4], [7, 0, 5]]);
        var startCopy = new PuzzleState([[2, 8, 3], [1, 6, 4], [7, 0, 5]]);
        var goal = new PuzzleState([[1, 2, 3], [8, 0, 4], [7, 6, 5]]);

        alert(goal.toString());

        assert(start.equals(startCopy));
        assert(!start.equals(goal));