public MDIParent1(AppModel model)
{
InitializeComponent();
this.AppModel = model;
listForm = new ListForm(model);
listForm.MdiParent = this;
listForm.Show();
treeForm = new TreeForm(model);
treeForm.MdiParent = this;
treeForm.Show();
RefreshStatusString();
childFormNumber = 2;
model.PointRemoved += RefreshStatus;
}