How do i secure a web.config file so my site code is hard to hack.

Hi

if i want to make a web.config site in VB.NET, do i then need some more code to secure the site code, so its harder to hack my site !? i know the server can be hacked and thats another story.
right now im looking on a solution for the site code, to make that strong and secure.
I mean so my database is secured and some webform to....
 
<?xml version="1.0"?> <configuration> <appSettings/> <connectionStrings> <add name="ConnectionStringDogs" connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\kennelenggaardDSNbase.mdb;Persist Security Info=True"/> <!--<add name="ConnectionStringDogs" connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\web\localuser\xxxxxx.dk\database\xxxxxxDSNbase.mdb"/>--> </connectionStrings> <system.web> ...