How to dynamically create and release the memory occupied by iframe_javascript skills

Recently participated in the development of a project. Since the project is a browser-based rich client (RIA) application, a large number of iframes are called in the page. Later tests found that the browser memory has remained high, and the more iframe pages are opened, the greater the memory usage, especially in the IE series browsers. Even if all open iframe pages are closed, the memory usage does not drop significantly. IE browser becomes very stuck when the memory usage reaches about 400M. The analysis found that the problem was caused by the iframe not being released, so the memory occupied by all closed iframes was released. Although it could not be completely released, the memory usage of the iframe would not keep growing, and the memory usage of the entire application was controlled at around 150M.

/** 
* 动态创建iframe 
* @param dom 创建iframe的容器，即在dom中创建iframe。dom可以是div、span或者其他标签。 
* @param src iframe中打开的网页路径 
* @param onload iframe加载完后触发该事件，可以为空 
* @return 返回创建的iframe对象 
*/ 
function createIframe(dom, src, onload){ 
//在document中创建iframe 
var iframe = document.createElement("iframe"); 

//设置iframe的样式 
iframe.style.width = '100%'; 
iframe.style.height = '100%'; 
iframe.style.margin = '0'; 
iframe.style.padding = '0'; 
iframe.style.overflow = 'hidden'; 
iframe.style.border = 'none'; 

//绑定iframe的onload事件 
if(onload && Object.prototype.toString.call(onload) === '[object Function]'){ 
if(iframe.attachEvent){ 
iframe.attachEvent('onload', onload); 
}else if(iframe.addEventListener){ 
iframe.addEventListener('load', onload); 
}else{ 
iframe.onload = onload; 
} 
} 

iframe.src = src; 
//把iframe加载到dom下面 
dom.appendChild(iframe); 
return iframe; 
} 

/** 
* 销毁iframe，释放iframe所占用的内存。 
* @param iframe 需要销毁的iframe对象 
*/ 
function destroyIframe(iframe){ 
//把iframe指向空白页面，这样可以释放大部分内存。 
iframe.src = 'about:blank'; 
try{ 
iframe.contentWindow.document.write(''); 
iframe.contentWindow.document.clear(); 
}catch(e){} 
//把iframe从页面移除 
iframe.parentNode.removeChild(iframe); 
}