public boolean getAltKey()
Used to indicate whether the 'alt' key was depressed during the firing
of the event. On some platforms this key may map to an alternative
key name.

 public short getButton()
During mouse events caused by the depression or release of a mouse
button, button is used to indicate which mouse button
changed state. The values for button range from zero to
indicate the left button of the mouse, one to indicate the middle
button if present, and two to indicate the right button. For mice
configured for left handed use in which the button actions are
reversed the values are instead read from right to left.

 public int getClientX()
The horizontal coordinate at which the event occurred relative to the
DOM implementation's client area.

 public int getClientY()
The vertical coordinate at which the event occurred relative to the DOM
implementation's client area.

 public boolean getCtrlKey()
Used to indicate whether the 'ctrl' key was depressed during the firing
of the event.

 public boolean getMetaKey()
Used to indicate whether the 'meta' key was depressed during the firing
of the event. On some platforms this key may map to an alternative
key name.

 public EventTarget getRelatedTarget()
Used to identify a secondary EventTarget related to a UI
event. Currently this attribute is used with the mouseover event to
indicate the EventTarget which the pointing device
exited and with the mouseout event to indicate the
EventTarget which the pointing device entered.

 public int getScreenX()
The horizontal coordinate at which the event occurred relative to the
origin of the screen coordinate system.

 public int getScreenY()
The vertical coordinate at which the event occurred relative to the
origin of the screen coordinate system.

 public boolean getShiftKey()
Used to indicate whether the 'shift' key was depressed during the
firing of the event.

 public  void initMouseEvent(String typeArg,
    boolean canBubbleArg,
    boolean cancelableArg,
    AbstractView viewArg,
    int detailArg,
    int screenXArg,
    int screenYArg,
    int clientXArg,
    int clientYArg,
    boolean ctrlKeyArg,
    boolean altKeyArg,
    boolean shiftKeyArg,
    boolean metaKeyArg,
    short buttonArg,
    EventTarget relatedTargetArg)
The initMouseEvent method is used to initialize the value
of a MouseEvent created through the
DocumentEvent interface. This method may only be called
before the MouseEvent has been dispatched via the
dispatchEvent method, though it may be called multiple
times during that phase if necessary. If called multiple times, the
final invocation takes precedence.