If you are working on a project in Visual Studio and are presented with the error: Name 'ConfigurationManager' is not declared you can easily resolve the error with a couple mouse clicks.
To resolve the error, all you have to do is open up the project properties by double-clicking on the "My Project" icon.
When the project properties page has loaded, click on the "References" link on the left hand side and the click on "Add"
When the "Add Reference" dialog box appears, click on the ".NET" tab and scroll down to find System.Configuration, highlight it and click "OK".
You will be returned to the Project Properties dialog window and you will see that the System.Configuration reference has now been added. Then, near the bottom of the window, under "Imported Namespaces", scroll down to find the System.Configuration reference and place a check mark next to it.
Now, you have successfully imported the required namespace and reference. Switching back to your code page, you can see that you're errors have all been resolved.
