监控页面后退前进，浏览器文档加载事件之pageshow、pagehide

<div class="inputwrap">
                        <i class="loginpwd_ico"></i>
                        <input class="jsInptPwd" maxlength="16" type="password" placeholder="" name="loginpwd">
                        <div class="jsPlaceholder input-place">请设置登录密码<i>（6-16位数字及字母组成）</i></div>
                    </div>

<div class="protocol-wrap agreement active">
             <span class="icon-cbk"></span>我已阅读并同意<br><a href="/f/special/member_protocol" >《金融服务协议》</a>
            </div>

window.addEventListener('pageshow', function(event) {
                setTimeout(function() {
                    if($(".jsInptPwd").val().trim() !=''){
                        $(".jsPlaceholder").hide();
                    }else{
                        $(".jsPlaceholder").show();
                    }
                }, 101);
});
$(".jsInptPwd").on('input propertychange',function(){
                
           $(this).val() != '' ? $(".jsPlaceholder").hide() : $(".jsPlaceholder").show();
 });