I am new to programming, trying to copy files from one location to another, trying to use app.config file in Visual Studio 2010. 

The config file is 

```
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="sourcePath" value="C:\Users\Public\TestFolder"/>
<add key="targetPath" value="C:\Users\Public\TestFolder\SubDir"/>
</appSettings>
</configuration>

```

The code to copy the file is

```
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace FileCopy
{
    class FileCopy
    {
        class SimpleFileCopy
        {
            static void Main()
            {
                string fileName = "test.txt";
                string sourcePath = System.Configuration.ConfigurationSettings.appSettings["sourcePath"];
                string targetPath = System.Configuration.ConfigurationSettings.appSettings["targetPath"];

                // Use Path class to manipulate file and directory paths.
                string sourceFile = System.IO.Path.Combine(sourcePath, fileName);
                string destFile = System.IO.Path.Combine(targetPath, fileName);

                // To copy a folder's contents to a new location:
                // Create a new target folder, if necessary.
                if (!System.IO.Directory.Exists(targetPath))
                {
                    System.IO.Directory.CreateDirectory(targetPath);
                }

                // To copy a file to another location and 
                // overwrite the destination file if it already exists.
                System.IO.File.Copy(sourceFile, destFile, true);

                // To copy all the files in one directory to another directory.
                // Get the files in the source folder. (To recursively iterate through
                // all subfolders under the current directory, see
                // "How to: Iterate Through a Directory Tree.")
                // Note: Check for target path was performed previously
               //       in this code example.
                if (System.IO.Directory.Exists(sourcePath))
                {
                    string[] files = System.IO.Directory.GetFiles(sourcePath);

                    // Copy the files and overwrite destination files if they already  exist.
                    foreach (string s in files)
                    {
                        // Use static Path methods to extract only the file name from the path.
                        fileName = System.IO.Path.GetFileName(s);
                        destFile = System.IO.Path.Combine(targetPath, fileName);
                        System.IO.File.Copy(s, destFile, true);
                    }
                }
                else
                {
                    Console.WriteLine("Source path does not exist!");
                }

                // Keep console window open in debug mode.
                Console.WriteLine("Press any key to exit.");
                Console.ReadKey();

            }
        }
    }
}

```

I get an error when I build the solution which says 'System.Configuration.ConfigurationSettings' does not contain a definition for 'appSettings'

What am I doing wrong? 
Thanks for the help.