1.这种写法：(function(){})()，同时注意：原生的异步对象的兼容性实例化方法
<script>
document.domain = "qq.com";
xmlHttp = (function() {
var f;
if(window.ActiveXObject) {
f = function() { return new ActiveXObject('Microsoft.XMLHTTP');};
} else if(window.XMLHttpRequest) {
f = function() { return new XMLHttpRequest();};
} else {
f = function() { return;};
}
return f;
})();
说明：定义一个函数，然后执行调用这个函数
查看地址：（chrome浏览器）
view-source:http://radio.t.qq.com/proxy.html 拓展参考文章：https://www.cnblogs.com/wisdo/p/5074419.html
2.页面尺寸大小变化，都修正iframe的高度。
JS：
$(document).ready(function () {
function fixHeight() {
var headerHeight = $("#switcher").height();
$("#iframe").attr("height", $(window).height()-54+ "px");
}
$(window).resize(function () {
fixHeight();
}).resize(); });
HTML：
<div id="switcher">
<div class="center">
<ul>
<div id="Device">
<li class="device-monitor"><a href="javascript:">
<div class="icon-monitor">
</div>
</a></li>
<li class="device-mobile"><a href="javascript:">
<div class="icon-tablet">
</div>
</a></li>
<li class="device-mobile"><a href="javascript:">
<div class="icon-mobile-1">
</div>
</a></li>
<li class="device-mobile-2"><a href="javascript:">
<div class="icon-mobile-2">
</div>
</a></li>
<li class="device-mobile-3"><a href="javascript:">
<div class="icon-mobile-3">
</div>
</a></li>
</div>
<li class="remove_frame"><a href="http://www.jq22.com/demo/jQuery-huandong20161108" title="移除框架">
</a></li>
</ul>
</div>
</div>
<div id="iframe-wrap">
<iframe id="iframe" src="http://www.jq22.com/demo/jQuery-huandong20161108" frameborder="0" width="100%">
</iframe>
</div>
</div>
3. ... ...