close current window button

I need to set up a close this window button on my animate project.

Currently I have set up the open.window() javascript

function openFunction(link) {

    window.open(link.href);

on the html page that my project is opened from and when I add the close.window() javascript

<!--start close window-->

function closeFunction() {

    window.close();

}

to the html5 page after it is published it works but I would prefer to build the close button in the Animate file so I don't overwrite the code when making an update.

I've tried the following actions in Animate and it doesn't work.

//close current window

this.closeWinBtn.addEventListener("click", closeCurrentWindow.bind(this));

function closeCurrentWindow()

{

  this.window.close();

  }

I believe I'm close. Any suggestions?

thank you