private void searchbtn_Click(object sender, EventArgs e)
        {
            Search_data obj = new Search_data();

            string[] Data_array = obj.searchbyname(searchnametxt.Text, "studentrecord.txt").Split('\n');

            for (int i = 0; i < Data_array.Length; i++)
            {
                list.Items.Add(Data_array[i]);
            }
        }