How to Decrypt the Stored Procedure in Sql Server 2008?

create  PROCEDURE sp_decrypt_sp (@objectName varchar(50))
 AS
 

 
 DECLARE  @OrigSpText1 nvarchar(4000),  @OrigSpText2 nvarchar(4000) , @OrigSpText3 nvarchar(4000), @resultsp nvarchar(4000)
 declare  @i int , @t bigint , @ct nvarchar(max)

 --get encrypted data
 SET @OrigSpText1= (SELECT top 1 ctext FROM syscomments  WHERE id = object_id(@objectName) order by colid)
 SET @OrigSpText2='ALTER PROCEDURE '+ @objectName +' WITH ENCRYPTION AS '+REPLICATE('-', 3938)
  EXECUTE (@OrigSpText2)
 print @OrigSpText1

 SET @OrigSpText3=(SELECT top 1 ctext FROM syscomments  WHERE id = object_id(@objectName) order by colid)
 SET @OrigSpText2='CREATE PROCEDURE '+ @objectName +' WITH ENCRYPTION AS '+REPLICATE('-', 4000-62)

--start counter
 SET @i=1
 --fill temporary variable
 SET @resultsp = replicate(N'A', (datalength(@OrigSpText1) / 2))
 
--loop
 WHILE @i<=datalength(@OrigSpText1)/2
 BEGIN
  --reverse encryption (XOR original+bogus+bogus encrypted)
 SET @resultsp = stuff(@resultsp, @i, 1, NCHAR(UNICODE(substring(@OrigSpText1, @i, 1)) ^
                                 (UNICODE(substring(@OrigSpText2, @i, 1)) ^
                                 UNICODE(substring(@OrigSpText3, @i, 1)))))
 print @resultsp
  SET @i=@i+1
 END
 --drop original SP
 --EXECUTE ('drop PROCEDURE '+ @objectName)
 --remove encryption
 --preserve case
 SET @resultsp=REPLACE((@resultsp),'WITH ENCRYPTION', '')
 SET @resultsp=REPLACE((@resultsp),'With Encryption', '')
 SET @resultsp=REPLACE((@resultsp),'with encryption', '')
 IF CHARINDEX('WITH ENCRYPTION',UPPER(@resultsp) )>0 
   SET @resultsp=REPLACE(UPPER(@resultsp),'WITH ENCRYPTION', '')
 --replace Stored procedure without enryption
 set @ct = (SELECT ctext FROM syscomments WHERE id = object_id(@objectName))
 print @ct
 execute( @resultsp)
 GO