动态为页面添加CSS样式文件引用

 1 if (document.createStyleSheet) { //IE
 2     document.createStyleSheet("./Themes/Default/MessageTip.css");
 3 }
 4 else { //Firefox, Chrome
 5     var stylesheet = document.createElement("link");
 6     stylesheet.href = "./Themes/Default/MessageTip.css";
 7     stylesheet.rel = "stylesheet";
 8     stylesheet.type = "text/css";
 9     document.getElementsByTagName("head")[0].appendChild(stylesheet);
10 }