Javascript JSLint "strict violation"

(function () {
	'use strict';
	var gracz;
	
	function Player(name) {
		this.name = name;
		this.skill = ['speed', 'power', 'strength'];
	}
	Player.prototype.szhowSKill = function () {
		function randomSKill() {
			var liczba = Math.floor(Math.random() * this.skill.length);
			return this.skill[liczba];
		}		
		window.console.log(randomSKill(this.skill));
	};
	
	gracz = new Player('Maciek');
	gracz.szhowSKill();
}());	http://4programmers.net/Forum/Webmastering?mode=submit&forumId=3

function randomSKill(tab) {
			var liczba = Math.floor(Math.random() * tab.length);
			return tab[liczba];
}

var that = this;

(function () {
	'use strict';
	var gracz;
	
	function Player(name) {
		var that;
		that = this;
		this.name = name;
		this.skill = ['speed', 'power', 'strength'];
	}
	Player.prototype.szhowSKill = function () {
		function randomSKill() {
			var liczba;
			liczba = Math.floor(Math.random() * that.skill.length);
			return that.skill[liczba];
		}
		window.console.log(randomSKill());
	};
	
	gracz = new Player('Maciek');
	gracz.szhowSKill();
	
}());

function Example() {
    this.someProperty = 'something';
}
Example.prototype.someMethod = function () {
    var that = this;
    function someInnerFunction() {
        return that.someProperty;
    }
    console.log(someInnerFunction());
};

var example = new Example();
example.someMethod();