【IE】兼容输入框placeholder显示

1、引入jquery.placeholder.js

<!--[if IE]>
    <script type="text/javascript" src="lib/jquery.placeholder.js"></script>
 <![endif]-->

2、初始化

//判断IE浏览器及版本低于IE9
var w = document.body.clientWidth;
var explorer = window.navigator.userAgent;
if (explorer.indexOf("MSIE") >= 0) {
    // 兼容placeholder
    $(function() {         
        $('input, textarea').placeholder();
    });    
}