why my code is not working properly

Revision 1
here my store procedure but its not working please tell me where i go wrong


ALTER PROCEDURE [dbo].[sp_insert_registration]
(

@fname varchar(50)= NULL,
@mname varchar(50)= NULL,
@lname varchar(50)= NULL,
@p_password varchar(50)= NULL,
@question varchar(50)=NULL,
@answer varchar(50)=NULL,
@person_address varchar(50)= NULL,
@gender varchar(50)= NULL,
@sponcorid varchar(50)= NULL,
@dob datetime= NULL,
@productname varchar(50)=NULL,
@payment varchar(50)= NULL,
@sponcorname varchar(50)= NULL,
@side varchar(50)= NULL,
@mobile varchar(50)= NULL,
@bankname varchar(50)= NULL,
@baccno varchar(50)= NULL,
@bankbranch varchar(50)= NULL,
@PAN varchar(50)= NULL,
@IFSC_code varchar(50)= NULL,
@email_id varchar(50)= NULL,
@member_status varchar(50)= NULL,
@flag bit=NULL,
@smart_pin varchar(100)=NULL,
@count_mem int=NULL,
@createddate datetime= NULL,
@is_activate bit= NULL,
@registrationid int= NULL,
@renewaldate datetime=NULL,
@regCode varchar(50)=NULL
)
AS
BEGIN

INSERT INTO Registration_Master
(
[fname]
,[mname]
,[lname]
,[p_password]
,[question]
,[answer]
,[person_address]
,[gender]
,[sponcorid]
,[dob]
,[productname]
,[payment]
,[sponcorname]
,[side]
,[mobile]
,[bankname]
,[baccno]
,[bankbranch]
,[PAN]
,[IFSC_code]
,[email_id]
,[member_status]
,[flag]
,[smart_pin]
,[count_mem]
,[renewaldate]
,[createddate]
,[is_activate]
)

VALUES
(

@fname,
@mname,
@lname,
@p_password,
@question,
@answer,
@person_address,
@gender,
@sponcorid,
@dob,
@productname,
@payment,
@sponcorname,
@side,
@mobile,
@bankname,
@baccno,
@bankbranch,
@PAN,
@IFSC_code,
@email_id,
@member_status,
@flag,
@smart_pin,
@count_mem,
@renewaldate,
@createddate,
1

)

END


-- i have used function for generate auto increment alpha numeric code this code --is working properly no issue
DECLARE @regid int
SET @regid=@@IDENTITY
DECLARE @RegistrationCode varchar(100)
DECLARE registrationcodeCursor CURSOR FOR
SELECT [dbo].[RegistrationCode]
(
'P4U',@fname,@mname,@lname,'000',@regid,'34',@dob
)
OPEN registrationcodeCursor
FETCH FROM registrationcodeCursor INTO @RegistrationCode
CLOSE registrationcodeCursor
DEALLOCATE registrationcodeCursor

UPDATE Registration_Master
SET regCode=@RegistrationCode
WHERE registrationid=@regid

--here again i have used function to take full name even this is working properly
DECLARE @regid1 int
SET @regid1=@@IDENTITY
DECLARE @usernm varchar(50)
DECLARE usernameCursor CURSOR FOR
SELECT [dbo].[fullusername]
(
@fname,' ',@mname,' ',@lname
)
OPEN usernameCursor
FETCH FROM usernameCursor INTO @usernm
CLOSE usernameCursor
DEALLOCATE usernameCursor

UPDATE Registration_Master
SET username=@usernm
WHERE registrationid=@regid1

--Pair Matching

--this code is not working properly
SET @count_mem=0

WHILE(@sponcorid !=NULL)
BEGIN
IF(@count_mem<2)
BEGIN
SET @count_mem=@count_mem+1
UPDATE Registration_Master SET regCode=@regCode,count_mem=@count_mem WHERE side=@side
END
ELSE IF(@count_mem=2)
BEGIN
SET @count_mem=@count_mem+1

UPDATE Registration_Master SET sponcorid=@sponcorid,count_mem=@count_mem
END
DECLARE @temp varchar(50)
SET @temp=@sponcorid

SET @count_mem=@count_mem+1

UPDATE Registration_Master SET sponcorid=@sponcorid WHERE regCode=@temp AND count_mem=@count_mem
END



SELECT registrationid, regCode, fname,mname,lname,username, p_password,question,answer, person_address, gender, sponcorid, dob,productname, payment, sponcorname, side, mobile, bankname, baccno,
bankbranch, PAN, IFSC_code, email_id, member_status, count_mem,smart_pin,createddate, is_activate
FROM Registration_Master

WHERE registrationid=@@IDENTITY