js getElementsByClassName

getElementsByClassName:
function getElementsByClassName(searchClass, domNode, tagName) {
    alert(searchClass);
    if (domNode == null) domNode = document;
    if (tagName == null) tagName = '*';
    var el = new Array();
    var tags = domNode.getElementsByTagName(tagName);
    var tcl = " "+searchClass+" ";
    for(i=0,j=0; i<tags.length; i++) {
        var test = " " + tags[i].className + " ";
        if (test.indexOf(tcl) != -1)
        el[j++] = tags[i];
    }

    alert(el);
    return el;
}

操作Cookie By JavaScript:
function getCookie(c_name)
{
    if (document.cookie.length>0)
  {
        c_start=document.cookie.indexOf(c_name + "=");
        if (c_start!=-1)
        {
            c_start=c_start + c_name.length+1;
            c_end=document.cookie.indexOf(";",c_start);
            if (c_end==-1)
                c_end=document.cookie.length;
            return decodeURIComponent(document.cookie.substring(c_start,c_end));
        }
    }
    return null;
}

function setCookie(c_name,value,expiredays)
{
    var exdate=new Date();
    exdate.setDate(exdate.getDate()+expiredays);
    document.cookie=c_name+ "=" +escape(value)+((expiredays==null) ? "" : ";expires="+exdate);
}
getCookie,setCookie,delCookie:

function setCookie(name,value)
{
  var Days = 30; //此 cookie 将被保存 30 天
  var exp  = new Date();    //new Date("December 31, 9998");
  exp.setTime(exp.getTime() + Days*24*60*60*1000);
  document.cookie = name + "="+ escape(value) +";expires="+ exp.toGMTString();
}
function getCookie(name)
{
  var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
  if(arr != null) return unescape(arr[2]); return null;
}
function delCookie(name)
{
  var exp = new Date();
  exp.setTime(exp.getTime() - 1);
  var cval=getCookie(name);
  if(cval!=null) document.cookie=name +"="+cval+";expires="+exp.toGMTString();
}

Event:
var EventUtil=new Object;
    //oTarget：目标；sEventType：事件名称；funName：事件触发的函数名；
    EventUtil.addEvent=function(oTarget,sEventType,funName){
        if(oTarget.addEventListener){//for DOM;
            oTarget.addEventListener(sEventType,funName, false);
        }else if(oTarget.attachEvent){
            oTarget.attachEvent("on"+sEventType,funName);
        }else{
            oTarget["on"+sEventType]=funName;
        }
    };

    EventUtil.removeEvent=function(oTarget,sEventType,funName){
        if(oTarget.removeEventListener){//for DOM;
            oTarget.removeEventListener(sEventType,funName, false);
        }else if(oTarget.detachEvent){
            oTarget.detachEvent("on"+sEventType,funName);
        }else{
            oTarget["on"+sEventType]=null;
        }
    };