To avoid this problem in any complicated stored procedures, initialize the variable to empty before using them in any string manipulation.

e.g.

Declare @MobileCode as varchar(50), @MobileCodeNew as varchar(50), @MobileCodeForN as varchar(50), @RCOOC as varchar(50)

select @MobileCode = ''

select @MobileCodeNew = ''

select @MobileCodeForN = ''

select @RCOOC = ''

-- do what you got to do!

-- do what you got to do!

PRINT 'BEFORE NEW SRNO STARTS @MobileCode= '+@MobileCode+' @MobileCodeNew ='+@MobileCodeNew+'@MobileCodeForN ='+@MobileCodeForN+'@RCOOC ='+@RCOOC+'@MobileCodeForN ='+@MobileCodeForN