/// <summary>
        /// check file size
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public bool CheckFileSize(string fileName)
        {
            FileInfo       file = new FileInfo(fileName);
            sampleDatabase db   = new sampleDatabase();

            if (file.Length > db.getDataStoreSize())//replace db.getDataStoreSize()
            {
                throw new ArgumentException("Not enough space in database");
            }
            else
            {
                return(true);
            }
        }
        /// <summary>
        /// Check file for dup content
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public bool CheckFileDup(string fileName)
        {
            sampleDatabase db = new sampleDatabase();

            using (StreamReader sr = File.OpenText(fileName))
            {
                string s = sr.ReadLine();
                if (Array.Exists(db.getSampleData(), element => element == s))
                {
                    throw new ArgumentException("Duplication error");
                }
                else
                {
                    return(true);
                }
            }
        }