JS操作Cookie记录radio控件的值

function saveCookie(){var types = document.getElementsByName("type");var chk = -1;for(var i=0;i<types.length;i++){        if(types[i].checked){        chk = i;        }}        if(chk == -1)    {//    alert("请选择一个批次");    jAlert('请选择你的登录角色', '提示');    return false;    }else{    CookieUtil.set("cookieType", types[chk].value);//    alert(CookieUtil.get("cookieType"));    return true;    } }var CookieUtil = {    get: function (name){        var cookieName = encodeURIComponent(name) + "=",            cookieStart = document.cookie.indexOf(cookieName),            cookieValue = null,            cookieEnd;                    if (cookieStart > -1){            cookieEnd = document.cookie.indexOf(";", cookieStart);            if (cookieEnd == -1){                cookieEnd = document.cookie.length;            }            cookieValue = decodeURIComponent(document.cookie.substring(cookieStart + cookieName.length, cookieEnd));        }         return cookieValue;    },        set: function (name, value, expires, path, domain, secure) {        var cookieText = encodeURIComponent(name) + "=" + encodeURIComponent(value);            if (expires instanceof Date) {            cookieText += "; expires=" + expires.toGMTString();        }            if (path) {            cookieText += "; path=" + path;        }            if (domain) {            cookieText += "; domain=" + domain;        }            if (secure) {            cookieText += "; secure";        }            document.cookie = cookieText;    },        unset: function (name, path, domain, secure){        this.set(name, "", new Date(0), path, domain, secure);    }};

<form action="mylogin" method="post">           <p class="denglu1"><input type="text" name="username" id="username" ></p>           <p class="denglu2"><input type="password" name="password" id="password"></p>            <table class="denglu4">           <tr>           <td width="250"> <c:if test="${error.message != null}"><img src="png/stop.png">${error.message}</c:if> </td>           <td width="180"><input type="radio"  name="type" value="student" class="denglu4"/> 学生    <input type="radio" name="type" value="inno_mentor"  class="denglu4"/> 导师</td>           </tr>           </table>               <p class="denglu3"><!-- <a href="notice.html">  --> <button type="submit" class="btn-large btn-primary btn-nor" onclick="return saveCookie()" >登 录</button></a><a href="toRegister"><button type="button" class="btn-large btn-primary btn-normal">立即注册</button></a></p></form>

<script type="text/javascript">window.onload=function()//用window的onload事件，窗体加载完毕的时候{var typevalue  = CookieUtil.get("cookieType");var types = document.getElementsByName("type");for(var i=0;i<types.length;i++){if(types[i].value == typevalue){types[i].checked = true;}}}</script>