js实现自动登陆的按钮

<style type="text/css">
    body,input,p{margin:0;padding:0px;}
    body{font-size:12px;line-height:22px;font-family:tahoma;}
    #content{margin:10px auto;width:170px;}
    input {margin-right:5px;vertical-align:middle;}
    #tips{display:none;margin:5px;padding:5px;border:1px #f90 solid;background:#ffefad;}
    #tips2{display:none;margin:5px;padding:5px;border:1px #f90 solid;background:#ffefad;}
</style>


<div id="content">
    <label><input type="checkbox" />自动登陆</label>
    <div id="tips">为了你的安全,请不要在网吧或公共电脑使用该功能
    </div>
    <div id="tips2">
        你已勾选自动登陆。
    </div>
</div>

<script>
    window.onload =function()
    {
        var obj=
        {
            tips:document.getElementById("tips"),
            lb:document.getElementsByTagName("label")[0],
            ip:document.getElementsByTagName("input")[0],
            div1:document.getElementById("tips2")

        };
        obj.lb.onmouseover=function(){
           obj.tips.style.display="block";
        }
         obj.lb.onmouseout=function(){
           obj.tips.style.cssText="display:none;";
        }
        obj.ip.onchange=function(){
            this.checked?obj.div1.style.display="block":obj.div1.style.display="none";
        }
    }
</script>