Is there a way to define a global variable inside a function in Bangle.js?

Hi,

I am a relatively new user of the Bangle.js. I was playing around with the button and touch functionality of the watch in the emulator.
I am trying to declare a global variable inside of a function. I am aware that the way to do this in JavaScript is to prepend the variable declaration with the word 'window', like below:
window.a = 'abc';

When I try to do the same inside my code, it is giving me an "Uncaught ReferenceError: "window" is not defined" error message.

Am I missing something here? I have uploaded my code snippet for reference.

// Load fonts
require("Font7x11Numeric7Seg").add(Graphics);
var IOString = "No Input";
function draw() {
  var d = new Date(), h = d.getHours(), m =
  d.getMinutes();
  var time = (" "+h).substr(-2) + ":" + ("0"+m).substr(-2);
  g.clear();
  g.setFont("7x11Numeric7Seg",4);
  g.setFontAlign(1,1); // align right bottom
  g.drawString(time, 160, 140, true /*clear background*/);
  g.setFont("7x11Numeric7Seg",2);
  g.drawString(("0"+d.getSeconds()).substr(-2), 190, 140, true);
  g.setFont("6x8");
  g.drawString(IOString, 70, 185, true); // draw the input
  window.a = 'abc';
}

var secondInterval = setInterval(draw, 100);
setWatch(() => {
  IOString = "Button 1";
}, BTN1, {repeat: true});
setWatch(() => {
  IOString = "Button 2";
}, BTN2, {repeat: true, edge: "falling"});
setWatch(() => {
  IOString = "Button 3";
}, BTN3, {repeat: true});
Bangle.on('swipe', (sDir) => {
  if (sDir==1) {
    window.secondInterval = setInterval(draw, 100);
    IOString = "Swipe left";
  } else {
    IOString = "Swipe right";
    clearInterval(secondInterval);
    g.clear();
    g.drawString(IOString, 120, 120);
  }
});
Bangle.on('touch', (sDir) => {
  if (sDir==1) {
    IOString = "Touch left";
  } else {
    IOString = "Touch right";
  }
});

I would like to set my secondInterval variable to be a global one, so that it can be cleared from outside the function where it is defined.

Any help would be greatly appreciated.

window is web browser window when javascript runs as part of web page, do you really expect web browser to be runing inside the watch? try global
see also https://javascript.info/global-object , it is same like in node.js

Ah yes! I got confused between the usage. Tried out using global and that works perfectly as expected.

Thanks for your help! :D