title: update web.config based on different server using asp.net
body: <p>i am looking for a easy &amp; elegant way to change my <code>appsettings</code> in web.config based on the different environment and i have (dev/qa/test/stage/prod) and i am manually changing the <code>appsettings</code> and its very tedious and time consuming and i have about dozens of settings.... what is the best approach for this kinda situation? i know one solution using <code>Environment variables</code> but wants to hear the best practice?</p>