Since your browser does not have Java-support you are not able to see the fractal.
Press the mousebutton where you want to zoom in, press any key to zoom back out again. The applet seems to "hang" sometimes, due to heavy calculation, just wait a while and it hopefully will wake up again. This applet is still in beta, that means there are quite a few bugs there.
This was stolen from Steffen Thorsen. Thanks, Steffen!