UiEvent detail Property
How many times was the mouse clicked:
detail property returns details about an event.
detail property is read-only.
click count from click and dblclick events.
click count + 1 from mousedown and mouseup events.
2 for a dblclick event.
0 for all other events.
The number of clicks that happened in a short amount of time.
|DOM Version:||DOM Level 2 UI Events|
event.detail is a DOM Level 2 (2001) feature.
It is fully supported in all browsers: