iframe设置自适应窗口
//获取窗口的大小
function changeFrameHeight(){
var ifm= document.getElementById("helper_page");
ifm.height=document.documentElement.clientHeight;
}
//检测窗口的大小变化
window.onresize=function(){
changeFrameHeight();
}
<iframe id="helper_page" frameborder="0" onload="changeFrameHeight()" scrolling="no" style="width: 100%;"></iframe>