document.getElementsByClassName = function(cl) {
		var retnode = [];
		var myclass = new RegExp('\\b'+cl+'\\b');
		var elem = this.getElementsByTagName('*');
		for (var j = 0; j < elem.length; j++) {
			var classes = elem[j].className;
			if (myclass.test(classes)) retnode.push(elem[j]);
		}
		return retnode;
	}
	
	// --- 隐藏所有
	function HideAll() {
		var items = document.getElementsByClassName("optiton");
		for (var j=0; j<items.length; j++) {
			items[j].style.display = "none";
		}
	}
	
	// --- 设置cookie
	function setCookie(sName,sValue,expireHours) {
		var cookieString = sName + "=" + escape(sValue);
		//;判断是否设置过期时间
		if (expireHours>0) {
			 var date = new Date();
			 date.setTime(date.getTime + expireHours * 3600 * 1000);
			 cookieString = cookieString + "; expire=" + date.toGMTString();
		}
		document.cookie = cookieString;
	}
	
	//--- 获取cookie
	function getCookie(sName) {
	  var aCookie = document.cookie.split("; ");
	  for (var j=0; j < aCookie.length; j++){
		var aCrumb = aCookie[j].split("=");
		if (escape(sName) == aCrumb[0])
		   //return unescape(aCrumb[1]);
		 return null;
	  }
	  return null;
	}
	
	window.onload = function() {
		var show_item = "opt_1";
		if (getCookie("show_item") != null) {
			 show_item= "opt_" + getCookie("show_item");
		}
		document.getElementById(show_item).style.display = "block";
		var items = document.getElementsByClassName("title");
		for (var j=0; j<items.length; j++) {
			items[j].onclick = function() {
				var o = document.getElementById("opt_" + this.name);
				if (o.style.display != "block") {
					HideAll();
					o.style.display = "block";
					setCookie("show_item",this.name);
				}
				else {
					o.style.display = "none";
				}
			}
		}
	}