Copyright (c) Xoetrope Ltd., 2001-2006, This software is licensed under
the GNU Public License (GPL), please see license.txt for more details. If
you make commercial use of this software you must purchase a commercial
license from Xoetrope.
Sets the viewboxs centre position on the map.
Parameters: x - double specifying the x coordinate of the view box's centre position. Parameters: y - double specifying the y coordinate of the view box's centre position.
Sets the size of the view box.
Parameters: w - double specifying the new width of the viewBox. Parameters: h - double specifying the new width of the viewBox.