public void bindGridView1()
 {
     try
     {
         Playlist pl = new Playlist();
         DataSet ds = pl.LoadAllMP();
         bool check = IsEmpty(ds);
         if (!check)
         {
             GridView1.DataSource = ds;
             GridView1.DataBind();
             Label1.Text = "";
             ViewStat["flag"] = "true";
         }
         else
         {
             Label1.Text = "No data found!";
         }
     }
     catch (Exception e)
     {
         Label1.Text = "The Server is down! Try again later!";
     }
 }
        protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
        {
            Playlist pl = new Playlist();
            DataSet ds;

            if (Page.IsPostBack)
            {
                // Retrieve and display the property value.
                flag = (string)ViewState["flag"];
            }

            if (flag == "true")
            {
                ds = pl.LoadAllMP();
            }
            else
            {
                ds = pl.LoadByLocationMP(txbLocation.Text);
            }

            int currentPage = GridView1.PageIndex;
            int pos = currentPage * 10;

            DataRow dr = ds.Tables[0].Rows[GridView1.SelectedIndex + pos];
            int index = (int)dr["id_playlist"];

            Music mus = new Music();
            DataSet ds2 = mus.LoadById_playlist(index);
            GridView2.DataSource = ds2;
            GridView2.DataBind();
        }