使用JS意识到自己主动提交表单

今天将需要chat集成到客户的网站上去，注册用户链接登录这个网站后点击实现网站直接登录chat向上。我不停chat原来的登录界面，采纳JS当页面跳转技术，随着时间的推移自己主动填写表格。自己主动提交表单，从而实现站点用户无需再次登录就可以进入chat。详细代码实现例如以下

JS代码

<script>
//取得cookie值
function getCookie(name){
var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
if(arr=document.cookie.match(reg)){
return unescape(arr[2]);
}else{
return null;
}
}

//表单自己主动提交函数
function tijiao(){
function sub(){
         var a = document.getElementById('loginForm');
         a.elements[2].value = getCookie('username');
         a.elements[3].value = getCookie('username');
         var opts = document.getElementById("channelField");
         opts[1].selected = 'selected';
         opts[0].selected = '';
         a.submit();
}
setTimeout(sub,0);//以毫秒为单位的.1000代表一秒钟.依据你须要改动这个时间.
}

//点击button提交表单
function clickbutton(obj){
obj.onclick = function(){
obj.submit();
}
}
</script>

HTML代码

<form id="loginForm" name="loginForm" action="[LOGIN_URL/]" method="post" enctype="application/x-www-form-urlencoded">
<div id="loginFormContainer" style="margin:0px;padding-bottom: 10px;">
<input type="hidden" name="login" id="loginField" value="login"/>
<input type="hidden" name="redirect" id="redirectField" value="[REDIRECT_URL/]"/>
<div><label for="userNameField">[LANG]userName[/LANG]：</label>
<input type="text" name="userName" id="userNameField" maxlength="[USER_NAME_MAX_LENGTH/]"/></div><br />
<div><label for="passwordField">[LANG]password[/LANG]*：</label>
<input type="password" name="password" id="passwordField"/><span style="margin-left:4px; color: #339900;">默认是您的username</span></div><br />
<div><label for="channelField">[LANG]channel[/LANG]：</label>
<select name="channelName" id="channelField">[CHANNEL_OPTIONS/]</select></div><br />
<div><label for="languageSelection">[LANG]language[/LANG]：</label>
<select id="languageSelection" name="lang" onchange="ajaxChat.switchLanguage(this.value);">[LANGUAGE_OPTIONS/]</select></div><br />
<!--
<div><input type="submit" name="submit" style="width: 240px;height: 50px;background: url(../chat/img/bglogin2.png);background-repeat: no-repeat;border: 0px;" id="loginButton" value=""/></div>
-->
<div><button name="subButton" onclick="clickbutton(this);" style="width: 240px;height: 50px;background: url(../chat/img/bglogin2.png);background-repeat: no-repeat;border: 0px;" id="loginButton" value=""></button></div>
</div>
</form>

PS：
1. 要在body中增加onload="tijiao();"
2. 另外表单的提交button（submit）须要隐去。不然会和js的submit()方法冲突，这里採用button提交，避免在自己主动登录失败时没这里提交button