function func(){
            //点击输入框内容为空;
            $('#signname').val("");
            $('#signtel').val("");            if(!uid || (uid.length == 0)){
                alert("请先登陆!!");
                window.location.href = '/index.php/Public/index';
                return false;//这里下面如果没有else---return false后的代码,alert后会继续执行;????
            }else{
                $('.shadow_div').css('display','table');//*****
                $('.content1').css('display','block');
                $('.content2').css('display','none');
                $('.content3').css('display','none');
            }
        }