html页面回车事件

<li><input type="text" id="account" name="account" placeholder="请输入用户名">
          <span class="falsehints" id="namets" style="display:none">用户名不能为空</span>
</li>
<li><input type="password" name="pwd" id="pwd"  placeholder="请输入密码" onkeydown='test()'>
           <span class="falsehints" id="passts" style="display:none">密码不能为空</span>

</li>
<li><p id="submit">登录</p></li>



<script>

function test(frm,event){
    var event=window.event?window.event:event;   
    if(event.keyCode==13){
        sub();
    }
}





function sub(){//登录操作

}

</script>