serlvet+JQ 已崩溃,请求帮助

serlvet:
public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        String name=request.getParameter("uname");
        PrintWriter out = response.getWriter();
                                           //使用io流把响应回传给C端
        if(name.equals("cc"))
        {
            out.println("yes");
        }
        else
        {
            out.println("no");
        }
        out.flush();
        out.close();
    }


js:
function sendRequest4()
{
        $.ajax({
           type:"POST",
           url:"GetName",
           data:{uname:$("#uname").val()},
           success:function (data)
           {
            alert(data);
            alert(data.length);
                if(data=="yes"){
                    $("#msg").html("<font color='red'>"+"该用户存在!"+"</font>");
                                                                                                           //代码一
                }
                else{
                    $("#msg").html("<font color='green'>该用户不存在!</font>");
                                                                                                           //代码二
                    });
                }
           }
        });
}

页面输入"cc"，alert(data)，打印"yes"，alert(data.length)，打印5
页面输入任何东西，alert(data)，打印"no"，alert(data.length)，打印4
yes 长度应该是3？no 长度应该是2？

程序始终不进入代码一部分，很是苦恼，length始终是5和4，请求帮助

问题已解决