Microsoft SQL 2008 "Saving changes is not permitted" solution

Reference:
http://weblogs.asp.net/coltk/archive/2009/12/26/saving-changes-is-not-permitted-in-sql-2008-management-studio.aspx

I used to write ALTER statement (e.g. ALTER Table.. .ALTER Column...) so I don't really know what is the error message mean. Today, I search it during my Xmas holiday and know that there's a option in Tools | Options | Designer | Prevent saving change that require table re-creation.