protected void Deletar_Click(object sender, EventArgs e)
        {
            try
            {
                Class_ItensVenda vend = new Class_ItensVenda();
                vend.cb = txtcb.Text;

                vend.deletar();
                GDItemVenda.DataSource = vend.visualizar();
                GDItemVenda.DataBind();
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
        }
        protected void GDItemVenda_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
            try
            {
                Class_ItensVenda classe = new Class_ItensVenda();
                classe.codlaboratorio = Convert.ToInt32(e.Values[0]);

                classe.deletar();

                GDItemVenda.EditIndex = -1;


                GDItemVenda.DataSource = classe.visualizar();
                GDItemVenda.DataBind();
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
        }