var reg=/^((ht|f)tps?):\/\/[\w\-]+(\.[\w\-]+)+([\w\-\.,@?^=%&:\/~\+#]*[\w\-\@?^=%&\/~\+#])?$/;
//判断输入url
        $("input",$("#url").next("span")).blur(function(){
            if($("#url").val()==""){
                $("#urlpd").css('display','block');
                $("#urlpd").text("请填写URL地址");
            }else if(!reg.test($("#url").val())){
                $('#urlpd').css('display','block');
                $("#urlpd").text("URL地址不正确");
            }else {
                $('#urlpd').css('display','none');
            }
        });