private void buttonNext_Click(object sender, EventArgs e) { if (textBoxRotation.Text != String.Empty) { ImageForm image = new ImageForm(); image.MdiParent = this.MdiParent; image.rotationValue(bmp_, Convert.ToDouble(textBoxRotation.Text), comboBoxMethod.SelectedItem.ToString()); image.Show(); } else MessageBox.Show("Indique un valor para la rotación"); }