private void but_agregar_editorial_Click(object sender, EventArgs e)
        {
            if (this.verificar_datos_editorial())
            {

                if (tex_direccion.Text.Length == 0)
                {
                    tex_direccion.Text = "";
                }

                StringBuilder errorMessages = new StringBuilder();
                Editorial edi = new Editorial();

                edi.v_nombre_editorial = tex_nombre_editorial.Text;
                edi.v_Dpais = com_pais.SelectedItem.ToString();
                edi.v_direccion_editorial = tex_direccion.Text;
                edi.v_usuario_i = this.usuario;

                try
                {
                    if (edi.AgregarEditorial(edi) != 0)
                    {
                        MessageBox.Show("Editorial creada correctamente" + "\n" +"Nombre: " + edi.v_nombre_editorial,
                        "Agregar Editorial",
                        MessageBoxButtons.OK,
                        MessageBoxIcon.Information);
                        this.inicializarDatos();
                    }
                }
                catch (SqlException ex)
                {
                    for (int i = 0; i < ex.Errors.Count; i++)
                    {
                        errorMessages.Append("Index #" + i + "\n" +
                        "Message: " + ex.Errors[i].Message + "\n" +
                        "LineNumber: " + ex.Errors[i].LineNumber + "\n" +
                        "Source: " + ex.Errors[i].Source + "\n" +
                        "Procedure: " + ex.Errors[i].Procedure + "\n");
                    }
                    Console.WriteLine(errorMessages.ToString());
                    this.inicializarDatos();
                    MessageBox.Show(ex.Errors[0].Message.ToString(),
                    "Agregar Editorial",
                    MessageBoxButtons.OK,
                    MessageBoxIcon.Warning);
                }
            }
        }