(function(){
	var init = function(){
		var rnd = Math.floor(Math.random()*3);
		var imgs = [];
		var contents = [];
		for(var i = 0; i < 3; i++){
			imgs[i] = document.getElementById("idx_key" + (i+1));
			contents[i] = document.getElementById("idx_keyImg" + (i+1));
			imgs[i].key = i;
			imgs[i].onmouseover = function(){
				switchImg(this.key);
			}
		}
		switchImg(rnd);
		function switchImg(key){
			for(var i = 0, l = contents.length; i < l; i++){
				contents[i].style.display = "none";
				imgs[i].src = imgs[i].src.replace("_act." , "_of.");
			}
			contents[key].style.display = "block";
			imgs[key].src = imgs[key].src.replace("_of.", "_act.");
		}
		
	}
	window.onload = init;
})();