If you encounter any errors with the inclusion of files, with connection at db, errors such as
Server.MapPath() error 'ASP 0175 : 80004005'
Disallowed Path Characters
/folder/subfolder/page.asp, line XX
The '..' characters are not allowed in the Path parameter for the MapPath method.
Microsoft VBScript runtime error '800a01ad'
ActiveX component can't create object: 'CDONTS.Newmail'
/pagina.asp, line xx

Read this vademecum page carefully.