Configure a control to be the same size as the pane by using the Fit Control to Pane option. The control becomes the same size as the pane and scales automatically when you resize the pane. The scroll bars on the pane also disappear.
You also can configure a control to scale automatically while the pane resizes. Right-click a splitter bar and select Pane Sizing»Scale Objects While Resizing from the shortcut menu. Any item that scales on the pane scales while you resize the pane instead of when you are finished resizing the pane.