void mouseDown( ) { ... }
void mouseDown( int x, int y) { ... }
The "mouseDown" method is invoked automatically each time the user depresses the mouse's button while the mouse is located within the region of the screen controlled by the applet. If the version of "mouseDown" declared in a particular applet expects two integer parameters, then the browser will pass as parameters the x and y coordinates of the mouse's screen position at the time the button was depressed.