JQ 点击指定文本框显示div。点击其他区域隐藏DIV

<input id="username" type="text" style="width:90%;margin-top: 40px;" placeholder="請輸入車場名稱或車場間稱" class="text_name" name="username"/>
<div class="text_div_all" style="display: none;">
<ul>
<li>张三3</li>
<li>张三1</li>
<li>张三2</li>
</ul>
</div> //点击搜索框显示点击其他区域隐藏
$(document).bind('click',function(e){
var e = e || window.event; //浏览器兼容性
var elem = e.target || e.srcElement;
while (elem) { //循环判断至跟节点，防止点击的是div子元素
if (elem.id && elem.id=='username') {
return;
}
elem = elem.parentNode;
}
$("#username").attr("value",$(".text_div_all ul li").html());
$('.text_div_all').css('display','none');
});