Once an xbmImage has been displayed, any subsequent changes to it will not be displayed when you redraw the frame. Netscape assumes that images of a given name don’t change, so it uses its cached copy after the first draw.
The workaround is to assign the xbmImage object to an object with a different name and then redraw it. The JS-Draw application, shown in the next section, uses an array for this purpose.
Ananova 