if nothing selected, clear out values

EduNetworkBuilder/ShapeEditor.cs

@@ -83,6 +83,18 @@ namespace EduNetworkBuilder
                 cbLineColor.Text = ShapeForEditing.LineColor.Name;
                 cbShape.Text = ShapeForEditing.MyShape.ToString();
             }
+            else
+            {
+                {
+                    tbX.Text = "0";
+                    tbY.Text = "0";
+                    tbHeight.Text = "0";
+                    tbWidth.Text = "0";
+                    cbFillColor.Text = "Empty";
+                    cbLineColor.Text = "Empty";
+                    cbShape.Text = "None";
+                }
+            }
         }
 
         private void btnDone_Click(object sender, EventArgs e)