How to handle ESC keydown on javascript popup window

I have a javascript window.open popup, and I want the popup to close itself when the user presses the ESC key. I can't figure out how to hook the keydown event (and on what object?) so that I can catch the ESC key.

I'm using jQuery.

Try something like this:

$(document).keydown(function(e) {
    // ESCAPE key pressed
    if (e.keyCode == 27) {
        window.close();
    }
});

It is possible to achieve with JS Without using jQuery.

window.onkeydown = function( event ) {
    if ( event.keyCode == 27 ) {
        console.log( 'escape pressed' );
    }
};

event.key === "Escape"

No more arbitrary number codes!

document.addEventListener('keydown', function(event) {
    const key = event.key; // const {key} = event; in ES6+
    if (key === "Escape") {
        window.close();
    }
});

Mozilla Docs

Supported Browsers

Remember that you must use the function @Gumbo posted in the popup-window... So you will need to include JQuery in the popup and execute the function there, not the window that opens the popup.

To handle both esc and enter key on dialog window.onkeydown = function(event) {

if(event.keyCode===27|| event.keyCode===13){
   window.close();
}
}