Problem in show error message when insert data into database

HI

I have insert.aspx page that users can enter data and when they click on insertbutton it insert data into database below is SP

create procedure [dbo].[InsertFreeState2]
@Name nvarchar(40)
,@mobile varchar(20)=null
,@Tell varchar(15)=null
,@Transfer nvarchar(20)
,@Type nvarchar(20)
,@id int =0
,@Result NVARCHAR(120) OUTPUT
 
 
 
AS BEGIN
 
IF ((NOT EXISTS(SELECT id FROM Estate_free WHERE (Mobil = @Mobile or Tell=@Tell))) AND  (NOT EXISTS(SELECT id FROM Black_List WHERE Mobile = @Mobile or Tell=@Tell)))
begin
        IF EXISTS(SELECT id FROM Estate_free WHERE id = @id AND @id > 0 )
            BEGIN
                    UPDATE Estate_free
                    SET
                            Name=@Name
                            ,Mobil=@mobile
                            ,Tell=@Tell
                            ,Transfer=@Transfer
                            ,Type=@Type
                            WHERE ID=@id
                            SELECT @id
                    SET @Result = 'you have been registered.'
            END
 
        ELSE
                BEGIN
                            INSERT INTO Estate_free(Name,Mobil,Tell,Transfer,Type)
                            VALUES(@Name,@Mobile,@Tell,@Transfer,@Type)
                            SET @Result = 'you have been registered.' 
                    END
     
     
 
        END
 ELSE
             begin
             SET @Result = 'you can just register 1 Time '
            END
END

 here when users enter new mobile number it should insert data into database and show 'You have been registered'  and if they enter Mobile number that was in table it shouldn't insert data into database and show=='You can just register 1 Time'

probelm is when I enter new mobile number it inserted  data into database but it showed this message'You can just register 1 Time'  but here it should show 'You have been registered'

I mean in both condition  it show this message 'You can just register 1 Time'

it never show this message='You have been registerd'

what should i do?

Best Regards

Neda