Using c# to make a file manager, getting an error when making an instance

I am following a beginner tutorial on making a file manager and getting an erro when trying to make an instance.

private static      fileManager instance;       // Instance of the fileManager
private string      path;                   // Holds the application path


public static fileManager Instance
{
    get
    {
        if (instance == null)
        {
        instance = new GameObject (fileManager).AddComponent ();
        }

        return instance;
    }
}