IE9不支持createContextualFragment属性

if ((typeof Range !== "undefined") && !Range.prototype.createContextualFragment) {
	         Range.prototype.createContextualFragment = function (html) {
	             var frag = document.createDocumentFragment(),
	            div = document.createElement("div");
	             frag.appendChild(div);
	             div.outerHTML = html;
	             return frag;
	         };
	     }