function leak1() { 
var node = document.getElementById("TO_AREA"); 
node.innerHTML = "<img />"; 
node.innerHTML = ""; 
node = null; 
} 

function leak2() { 
var node = document.getElementById("FROM_AREA").cloneNode(true); 
node.id = "NEW_AREA"; 
document.body.appendChild(node); 
document.body.removeChild(node); 
node = null; 
}

function leak4() { 
var node = document.createElement("IMG"); 
document.body.appendChild(node); 
document.body.removeChild(node); 
}

<script>
function clearRAM() {
var frame = document.getElementById("ifr_content");
frame.src = 'about:blank';
frame.contentWindow.document.write( '');//清空frame的内容
frame.contentWindow.document.clear();
frame.contentWindow.close(); //避免frame内存泄漏
if (navigator.userAgent.indexOf('MSIE') >= 0) {
if (CollectGarbage) {
CollectGarbage(); //IE 特有 释放内存
//删除原有标记
var tags = document.getElementById("ifrSet");
tags.removeChild(frame);
//添加frameset框架
var _frame = document.createElement('frame');
_frame.src = '';
_frame.name = 'content';
_frame.id = 'ifr_content';
tags.appendChild(_frame);
}
}
}
//主动释放 5秒一次
setInterval( function() {
if (navigator.userAgent.indexOf('MSIE') >= 0) {
if (CollectGarbage) {
//alert(1)
CollectGarbage(); //IE 特有 释放内存
}
}
}, 5000) 
</ script>