help with converting to JApplet

hi, i have done up my program using implements JFrame... i wants to make it a JApplet...

but when i compile it give me a error saying "cannot find symbol method addWindowListener(<anonymous java.awt.event.WindowAdapter>)"

i try to run my program using JFrame and everything is normal... but i can't convert it to applet... please help me. thank you.

cannot find symbol method addWindowListener(<anonymous java.awt.event.WindowAdapter>)"
windowClosing is handled by an applets AppletContext. You should not need a WindowListener for an applet.

my program is supposed to display a summary of things my program have stored into various array... is there another way around?