Clone database user in SQL Server 2005

SET NOCOUNT ON

DECLARE @OldUser sysname, @NewUser sysname

SET @OldUser = 'pwebstud'
SET @NewUser = 'pwebstaff'

SELECT 'USE' + SPACE(1) + QUOTENAME(DB_NAME()) AS '--Database Context'

SELECT '--Cloning permissions from' + SPACE(1) + QUOTENAME(@OldUser) + SPACE(1) + 'to' + SPACE(1) + QUOTENAME(@NewUser) AS '--Comment'

SELECT 'EXEC sp_addrolemember @rolename ='
+ SPACE(1) + QUOTENAME(USER_NAME(rm.role_principal_id), '''') + ', @membername =' + SPACE(1) + QUOTENAME(@NewUser, '''') AS '--Role Memberships'
FROM sys.database_role_members AS rm
WHERE USER_NAME(rm.member_principal_id) = @OldUser
ORDER BY rm.role_principal_id ASC

SELECT CASE WHEN perm.state <> 'W' THEN perm.state_desc ELSE 'GRANT' END
+ SPACE(1) + perm.permission_name + SPACE(1) + 'ON ' + QUOTENAME(USER_NAME(obj.schema_id)) + '.' + QUOTENAME(obj.name)
+ CASE WHEN cl.column_id IS NULL THEN SPACE(0) ELSE '(' + QUOTENAME(cl.name) + ')' END
+ SPACE(1) + 'TO' + SPACE(1) + QUOTENAME(@NewUser) COLLATE database_default
+ CASE WHEN perm.state <> 'W' THEN SPACE(0) ELSE SPACE(1) + 'WITH GRANT OPTION' END AS '--Object Level Permissions'
FROM sys.database_permissions AS perm
INNER JOIN
sys.objects AS obj
ON perm.major_id = obj.[object_id]
INNER JOIN
sys.database_principals AS usr
ON perm.grantee_principal_id = usr.principal_id
LEFT JOIN
sys.columns AS cl
ON cl.column_id = perm.minor_id AND cl.[object_id] = perm.major_id
WHERE usr.name = @OldUser
ORDER BY perm.permission_name ASC, perm.state_desc ASC

SELECT CASE WHEN perm.state <> 'W' THEN perm.state_desc ELSE 'GRANT' END
+ SPACE(1) + perm.permission_name + SPACE(1)
+ SPACE(1) + 'TO' + SPACE(1) + QUOTENAME(@NewUser) COLLATE database_default
+ CASE WHEN perm.state <> 'W' THEN SPACE(0) ELSE SPACE(1) + 'WITH GRANT OPTION' END AS '--Database Level Permissions'
FROM sys.database_permissions AS perm
INNER JOIN
sys.database_principals AS usr
ON perm.grantee_principal_id = usr.principal_id
WHERE usr.name = @OldUser
AND perm.major_id = 0
ORDER BY perm.permission_name ASC, perm.state_desc ASC