visual studio 2010 - .NET 4.0 and his Web.Config's XDT -

I'm trying to use XDT in the 4.0 web application and I do not know how! I know that this is probably weird (at least, since then I have read the thread, it seems easy for everyone, but I, no, me !!). Nothing is working, here is what I have tried:

Here is my web. Debug Config:

  & lt ;? Xml version = "1.0"? & Gt; & Lt; Configuration xmlns: xdt = "http://schemas.microsoft.com/XML-Document-Transform" & gt; & Lt; App Settings xdt: Transform = "Change" & gt; & Lt; Add key = "ConnectionString.SQL server (SqlClient)" value = "data source = test; initial list = testdb; user id = password; test = testpsw; security information continues = false; packet size = 4096" /> ; & Lt; / AppSettings & gt; & Lt; ConnectionStrings xdt: transform = "change" & gt; & Lt; Add name = "ASP.net authentication" connectionString = "data source = (local); initial catalog = testdb; user id = SA; password = testps; security alert continues =" /> & Lt; / ConnectionStrings & gt; & Lt; / Configuration & gt;  

My web In configurations, I'm getting more and more things but I want to change them.

  & lt ;? Xml version? = "1.0" & gt; [...] & lt; Configuration & gt; & Lt; AppSettings & gt; & Lt; Add key = "ConnectionString.SQL server (SqlClient)" value = "data source = [this will change]; initial list = [this will change]; user id = [this will change]; password = [this will change]; Continue protection information = false; packet size = 4096 "/> & Lt; / AppSettings & gt; & Lt; ConnectionStrings & gt; & Lt; Add name = "ASP.net authentication" connectionString = "data source = [this will change]; initial list = [this will change]; user id = [this will change]; password = [this will change]; security information = Wrong "/> & Lt; / ConnectionStrings & gt; & Lt; / Configuration & gt; [...]  

Am I doing wrong?

Note: I have read the post from MSDN and it does not help me ...

To make a web.config change on a web application, you have to deploy the project. Right click on the project and go to Publish.

Building a single project will not change locally.