IFRAME高度自适应——框架高度等于其页面高度

<iframe >function SetWinHeight(obj)
{
    var win=obj;
    if (document.getElementById)
    {
        if (win && !window.opera)
        {
            if (win.contentDocument && win.contentDocument.body.offsetHeight) 
                win.height = win.contentDocument.body.offsetHeight;
            else if(win.Document && win.Document.body.scrollHeight)
                win.height = win.Document.body.scrollHeight;
        }
    }
}