DECLARE @type varchar(50), @timestamp DATETIME, @user VARCHAR(100)

SELECT  @type=CASE WHEN [type] = 'U'
THEN 'TABLE'
 WHEN [type] = 'V'
THEN'VIEW'
 WHEN [type] = 'P'
THEN 'PROCEDURE
 WHEN [type] = 'PK'
THEN 'PRIMARY_KEY_CONSTRAINT'
 WHEN [TYPE] = 'D'
THEN 'DEFAULT_CONSTRAINT'
 WHEN [type] = 'FN'
THEN 'SQL_SCALAR_FUNCTION'
END 
FROM sys.objects
 WHERE [NAME] =  '|ObjectName|'

SELECT @timestamp=GETDATE()

SELECT @user=SYSTEM_USER


EXEC sys.sp_addextendedproperty @name=N'Created by', @value=@user , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=@type,@level1name=N'|ObjectName|'

EXEC sys.sp_addextendedproperty @name=N'Purpose', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=@type,@level1name=N'|ObjectName|'

EXEC sys.sp_addextendedproperty @name=N'Created on', @value=@timestamp, @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=@type,@level1name=N'|ObjectName|'
GO