an error...hmm

[PT Exorcist]

error line(the second line)

            devFunctions dFunction = new devFunctions();

dFunction.receivedData += new LiNG_BiNG.Classes.devFunctions.receivedWebData(receivedPicture); 

        private void receivedPicture(byte[] data)
        {
            MemoryStream mS = new MemoryStream(data);
            this.Image = Image.FromStream(mS);
        } 

    public class devFunctions
    {
        /// <summary>
        /// Gets the max number of Columns a devTab can get without spacing between pictures
        /// </summary>
        /// <param name="widthOfPictures">The size in pixels of the picture</param>
        /// <param name="widthOfTab">The size in pixels of the devTab</param>
        public static int getNumberOfColumns(int widthOfPictures, int widthOfTab)
        {
            double res = (double)widthOfTab / (double)(widthOfPictures);
            return (int)Math.Floor(res);
        }

        /// <summary>
        /// Gets the width in Pixels of each one of the borders of a devTab
        /// </summary>
        /// <param name="numberOfPictures">Number of pictures being populated into the devTab</param>
        /// <param name="widthOfPictures">Width in pixels of the pictures being used</param>
        /// <param name="widthOfTab">Width in pixels of the devTab being used</param>
        public static int getSizeOfBorders(int numberOfPictures, int widthOfPictures, int widthOfTab)
        {
            int res = numberOfPictures * widthOfPictures;
            return (widthOfTab - res) / 2;
        }

        /// <summary>
        /// Delegate for receiving data through downloadData() function
        /// </summary>
        public delegate void receivedWebData(byte[] data);

        /// <summary>
        /// Event that fires when web data is received from downloadData() function
        /// </summary>
        public event receivedWebData receivedData;

        public string downloadURL;

        /// <summary>
        /// Downloads an text or binary file from the internet
        /// </summary>
        /// <param name="url">The url of the file to be downloaded</param>
        public void downloadData(string url)
        {
            try
            {
                downloadURL = url;
                System.Threading.Thread thread =
                    new Thread(new System.Threading.ThreadStart(downloaddata));
            }
            catch (Exception e)
            {
                string err = "There was an error while creating a new thread\n" + e.Message;
                throw (new Exception(err));
            }
        }

        private void downloaddata()
        {
            WebClient web = new WebClient();
            receivedData(web.DownloadData(downloadURL));
        }
    } 

error:
C:\Documents and Settings\JBRANCO\My Documents\Visual Studio Projects\LiNG BiNG\Classes\devButton.cs(95): Cannot access a nonstatic member of outer type 'LiNG_BiNG.Classes.devButton' via nested type 'LiNG_BiNG.Classes.devButton.devButtonOptions'


i am not getting the problem here..any help