protected void btnCadastrar_Click(object sender, EventArgs e)
        {
            tb_instrumento i = new tb_instrumento()
            {
                nome          = txtNome.Text,
                tipo          = txtTipo.Text,
                familia       = txtFamilia.Text,
                dt_fabricacao = Convert.ToDateTime(txtDtFabricacao.Text)
            };

            dbintrumentosEntities dbi = new dbintrumentosEntities();

            string valor = Request.QueryString["idItem"];

            if (String.IsNullOrEmpty(valor))
            {
                dbi.tb_instrumento.Add(i);
            }
            else
            {
                int            id          = Convert.ToInt32(valor);
                tb_instrumento instrumento = dbi.tb_instrumento.First(c => c.id == id);
                instrumento.nome          = i.nome;
                instrumento.tipo          = i.tipo;
                instrumento.familia       = i.familia;
                instrumento.dt_fabricacao = i.dt_fabricacao;
            }

            dbi.SaveChanges();
        }
        protected void btnConsultar_Click(object sender, EventArgs e)
        {
            dbintrumentosEntities dbi = new dbintrumentosEntities();

            dbi.tb_instrumento.Find.by
        }