ZVON > References > DOM2 Reference

button (attribute )

Owning interface and usage:  
MouseEvent.button

Member of these other interfaces:  
none

Readonly:   yes

Type:   unsigned

Description:  
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.