public void QuickSearchproduct123()
    {
        ds100 = quicksearch.select_product_type();
        if (ds100.Tables[0].Rows.Count != 0)
        {
            for (int k = 0; k <= ds100.Tables[0].Rows.Count - 1; k++)
            {
                example = Convert.ToString(ds100.Tables[0].Rows[k]["product_type"].ToString());
                int z = Convert.ToInt32(ds100.Tables[0].Rows[k]["company_id"].ToString());
                string[] me = example.Split(',');
                int i;
                for (i = 0; i <= me.Length - 1; i++)
                {
                    Label3.Visible = false;
                    try
                    {
                        if (me[i] == DropDownList7.SelectedItem.Text)
                        {
                            try
                            {
                                quicksearch.get_company_id = z;
                                ds = quicksearch.companysearch();
                                if (ds.Tables[0].Rows.Count != 0)
                                {
                                    Label3.Visible = false;
                                    GridView dg = new GridView();
                                    dg.AllowPaging = true;
                                    dg.PageSize = 50;
                                    dg.Width = 50;
                                    dg.Height = 50;
                                    dg.DataSource = ds;
                                    dg.DataBind();

                                    Panel5.Visible = true;
                                    Panel5.Controls.Add(dg);
                                    flag = 1;
                                }
                                else
                                {
                                //  Page.ClientScript.RegisterStartupScript(this.GetType(), "msg", "");
                                    Panel5.Visible = false;
                                }
                            }
                            catch (Exception ex)
                            { }
                        }
                        else
                        {
                        }
                    }

                    catch (Exception ex)
                    {
                       // Page.ClientScript.RegisterStartupScript(this.GetType(), "msg", "");
                    }
                }
                if (flag==0)
                {
                    //Page.ClientScript.RegisterStartupScript(this.GetType(), "msg", "");
                                    
                    Panel5.Visible = false;
                }
                PagedDataSource page = new PagedDataSource();
                page.AllowPaging = true;
            }
        }
        else
        {
           // Page.ClientScript.RegisterStartupScript(this.GetType(), "msg", "");
        }
        if (flag == 0)
        {
            Page.ClientScript.RegisterStartupScript(this.GetType(), "msg", "");

            Panel5.Visible = false;
        }

    }
..................call this method in the button click event..........
here i take a panel and make this false in property........
pageload()
{if (!IsPostBack)
        {}
Panel5.Visible = false;

}