Trace child index number?

1

Hey guys I want to know the index number of the object when I clicked it…

trace(mc.getChildAt(0)) = display the object at the index 0 lets say the output is [object] button

now I want to reverse it…

when i click the object button

button.addEventListener(MouseEvent.CLICK, onClick)

function onClick(e:MouseEvent)
{
trace(e.currentTarget.???)

//I want to trace what index number is that button, the output should be “0”

}