js 如何通过js脚本动态加载js文件及读写cookie

在前端开发中，我们不免用到读写cookie，动态引入js脚本等相关操作，怎么实现呢？请参阅下面的js函数：

var JsHelper={
	CreateJS: function(url) { 
		var h = document.getElementsByTagName("head")[0];
		var s = document.createElement("SCRIPT");
		s.charset = "UTF-8";
		s.src = url;
		h.appendChild(s);
	},
    	SetCookieByDays: function(name, value, Days, domainValue) {
	        var cookieValue = name + "=" + escape(value);
        	if (domainValue != null)cookieValue += ";
		domain=" + domainValue;
       		if (Days != null && Days != 0) {
			var exp = new Date();
			exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000); 
			cookieValue += ";expires=" + exp.toGMTString();
		}
	        document.cookie = cookieValue;
    	},
       GetCookie: function(name) {
		var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));
		if (arr != null) return unescape(arr[2]); 
		return null;
	},
    	QueryString: function(item) {
		var sValue = location.search.match(new RegExp("[\?\&]" + item + "=([^\&]*)(\&?)", "i"));
		return sValue ? sValue[1] : sValue
	}
};