Selecting the Options - Fence - Zoom command causes the rectangle cursor to appear. To zoom in an area of the model:

1. Move the mouse to one corner of the area to be zoomed in.
2. While holding down the left mouse button, drag the mouse to the opposite corner of the desired area.
3. Release the mouse button.

The screen will redraw with the selected area enlarged so that the fenced area occupies the entire screen.

Note that the zoom functions do not effect the current mode of operation. For example, if while laying down a slab edge, a zoom command is issued, upon completion of the command you can continue with adding slab edges without re-invoking the Layout - Slab - Slab Edge command.