How to detect right-click on script UI button? - adobe-indesign

Question

Using Adobe InDesign's extendscript (javascript language), how can I add an onClick function for both left AND right click events?
Adding the left-click event is easy. How do I add the right-click event?
[post answer update (much thanks to Josh Voights for finding that)]
If anyone is interested, I wanted to use this in such a way to apply the handler to the button like this, which works perfectly:
whatbutton.addEventListener("click", function(p){
if(!p.shiftKey){
if (p.button ==2) {
alert("right click");
}else{
alert("left click");
}
}else{
if (p.button ==2) {
alert("shift right click");
}else{
alert("shift left click");
}
}

Answer 1

Here's a code sample from kahrel.plus.com/indesign/scriptui.html that includes watching for a right click. Credit to #fabiantheblind in this stackoverflow answer.
var w =new Window ("dialog");
var b = w.add ("button", undefined, "Qwerty");
b.addEventListener("click", function (k){whatsup (k)});
function whatsup (p)
{
if(p.button == 2){ $.writeln ("Right-button clicked.") }
if(p.shiftKey){ $.writeln ("Shift key pressed.") }
$.writeln ("X: "+ p.clientX);
$.writeln ("Y: "+ p.clientY);
}
w.show ();