Mr. Koirala Plz check it and help me out

Question

Hi Shiv, I need one favor, once i was going through the Article [Implement Code Behind in Share Point] on share Point by you in Code Project. it was really nice and i Implemented the same thing in my Share Point Application, it was nice even i was easily able to Connect to my Line of Business Database instead of BDC and all. I just wanted to know that in the same article you had added the Class Library and Inherit that Particular class[_default] by LayoutsPageBase and after that in the Layouts you added the Custom Asp.Net Page and Inherit that page from the Class[_default] of Library. but what i need actually, i don't want to use the Layouts Feature and the Layout Master page. i just wanted to use the Default master page of website through Share Point Designer, Actually i tried this but it was giving the Issue like
Parser Error Message: The base type 'ServicePointLibrary.Classes._Default' is not allowed for this page. The type is not registered as safe.

<%@ Page Language="C#" MasterPageFile="~masterurl/default.master" Inherits="ServicePointLibrary.Classes._Default" EnableViewState="false" EnableViewStateMac="false" %>

Even i Registerd the DLL in the SafeControl Also. but it was not happening.

First I created the ClassLibrary then I inherit that Class by Microsoft.SharePoint.WebPartPages.WebPartPage and Installed in GAC
After that Created one Asp.Net page from Share Point Designer and Inherit that Page from the Class of Library that is there in GAC, After that I got the Above Issue, i hope you got what i am trying to do. I think its Possible, am i doing right, Please Help me out.

With Regrards
Arshad Khan.