private void button7_Click(object sender, EventArgs e)
        {
            OpenFileDialog fb = new OpenFileDialog();

            fb.Filter = "Excel Office | *.xls; *.xlsx";

            if (fb.ShowDialog() == DialogResult.OK)
            {
                FileStream       strem    = new FileStream(fb.FileName, FileMode.Open, FileAccess.Read);
                IExcelDataReader exReader = ExcelReaderFactory.CreateReader(strem);
                DataSet          ds       = exReader.AsDataSet(new ExcelDataSetConfiguration()
                {
                    ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
                    {
                        UseHeaderRow = true
                    }
                });

                List <Tasks> tk = new List <Tasks>();
                Tasks        t;
                for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                {
                    t = new Tasks();
                    for (int j = 0; j < ds.Tables[0].Columns.Count; j++)
                    {
                        //if (j == 0)
                        //    t.Task_ID = Convert.ToInt32(ds.Tables[0].Rows[i][j].ToString());
                        if (j == 0)
                        {
                            t.Tittle = ds.Tables[0].Rows[i][j].ToString();
                        }
                        //else if (j == 2)
                        //    t.Date = ds.Tables[0].Rows[i][j].ToString();
                        else if (j == 1)
                        {
                            t.Time = ds.Tables[0].Rows[i][j].ToString();
                        }
                        //else if (j == 4)
                        //    t.RepeatDateTask_ID = ds.Tables[0].Rows[i][j].ToString();
                        else if (j == 2)
                        {
                            t.Description = ds.Tables[0].Rows[i][j].ToString();
                        }
                        else if (j == 3)
                        {
                            t.Priority = Convert.ToInt32(ds.Tables[0].Rows[i][j].ToString());
                        }
                        //else if (j == 7)
                        //    t.Category_ID = cat_ID;
                        //else
                        //    t.Task_Complete = Convert.ToInt32(ds.Tables[0].Rows[i][j].ToString());
                    }
                    t.RepeatDateTask_ID = System.Guid.NewGuid().ToString();
                    t.Category_ID       = cat_ID;
                    tk.Add(t);
                }
                exReader.Dispose();
                strem.Dispose();
                ds.Dispose();

                TaskSer tkSer = new TaskSer();

                for (int i = 0; i < tk.Count; i++)
                {
                    tkSer.InsertFormImportFile(tk[i]);
                }

                MessageBox.Show("File Is Imported");

                LoadTaskList();
            }
        }