The source code

    /**
     * @ignore
     * shim for ie6 ,require box-ext
     * @author yiminghe@gmail.com
     */
    KISSY.add("component/extension/shim-render", function () {
        // only for ie6!
        function Shim() {
        }

        Shim.prototype = {
            __createDom: function () {
                this.get("el").prepend("<" + "iframe style='position: absolute;" +
                    "border: none;" +
                    // consider border
                    // bug fix: 2012-11-07
                    "width: expression(this.parentNode.clientWidth);" +
                    "top: 0;" +
                    "opacity: 0;" +
                    "filter: alpha(opacity=0);" +
                    "left: 0;" +
                    "z-index: -1;" +
                    "height: expression(this.parentNode.clientHeight);" + "'/>");
            }
        };

        return Shim;
    });