private void btnSubtopic_Click(object sender, EventArgs e)
{
var a = NodeController.Get_Node_Selected();
if (a != null)
{
Node node = new Node();
node.Location = new Point(a.Location.X + a.Width + 50, a.Location.Y);
node.RefeshMidpoint();
node.Tag = NodeController.GetNumTag();
(Parent as MainPage).Addnode(node);
NodeController.Connect(a);
NodeController.Connect(node);
NodeController.Reefeshpaint();
(Parent as MainPage).Controls.Find("panelPaint", true).SingleOrDefault().Refresh();
}
}