动态添加内框iframe

var f = document.createElement("iframe");
    f.style.border = "0";
    f.style.width = "0";
    f.style.height = "0";
    document.body.appendChild(f);

    var d = f.contentWindow.document;
    d.write("<script type=\"text/javascript\">window.parent.escape = escape;<\/script>");
    d.close();