Please wait until the image is entirely downloaded.
To select a figure, just click on one corner of the figure, hold the mouse button and adjust the rubber band to encompass the entire figure. If the figure is larger than the applet area, the visible portion of will follow your mouse pointer.
Please have a look at Help for Dexter to get more information.
EDP has made some slight modifications to Dexter. You can download a unified diff of the modifications here.