This image is a Java Applet and is visible only on Java competent browsers. Pointing on the exons will make appear in the status window (the grey bar at the bottom of this window the name of the exon (and its group if any)). Clicking on them will lead to an alignment where the corresponding sequence will be coloured.
Due to the high number of zones the applet could be a little bit long to start, but after that it will go high speed...