move view:
1. Click on an empty area in the view and drag the mouse
with the left button pressed.
or
2. Navigate by using the arrow keys.
Zoom in and zoom out:
1. Press S-Key, click on an empty area in the view and drag
the mouse with left button pressed Taste horizontally.
or
2. Use CTRL- and arrow keys.
Rotate view (about 45 degree):
clockwise: press PgUp key
counter-clockwise: press PgDn key
select objects:
Next object: TAB
previos object: SHIFT-TAB
deselect: ESC