private void traingleGridToolStripMenuItem_Click(object sender, EventArgs e) { try { this.removeGridToolStripMenuItem_Click(sender, e); ShapeOverlay triangleOverlay = new TriangleOverlay(); this.originalImageBox.Image = triangleOverlay.CreateGrid(this.originalImageBox.Image, this.BlockSizeTextBox); } catch (Exception) { MessageBox.Show(@"oops! Must be an integer!"); } }