private void btnDrawLine_Click(object sender, System.EventArgs e) { MYPOINT pt1; MYPOINT pt2; pt1.xPos = 100; pt1.yPos = 100; pt2.xPos = 400; pt2.yPos = 400; // Validate base class. // (System.ValueType). MessageBox.Show(pt1.GetType().BaseType.ToString()); DrawerClass draw = new DrawerClass(); draw.DrawALine(ref pt1, ref pt2); }