更换页面EasyUI主题

function changetheme(str){
    $("body").fadeOut('fast',function(){
        var links = document.getElementsByTagName("link");
        var link = null;
        for (var i = 0; i < links.length; i++) {
            if(links[i].href.substr(-10) == "easyui.css"){
                link = links[i];
            }
        }
        link.href="${pageContext.request.contextPath}/easyui/themes/"+str+"/easyui.css";
        
        //对iframe进行更换主题
        var iframes = document.getElementsByTagName('iframe');
        for (var i = 0; i < iframes.length; i++) {
            links = iframes[i].contentDocument.getElementsByTagName('link');
            for (var j = 0; j < links.length; j++) {
                if(links[j].href.substr(-10) == "easyui.css"){
                    link = links[j];
                }
            }
            link.href="${pageContext.request.contextPath}/easyui/themes/"+str+"/easyui.css";
        }
        //删除变量降低内存占用
        i = null;
        j = null;
        links = null;
        link = null;
    });
    $("body").fadeIn();
}