How can I add a JavaScript keyboard shortcut to an existing JavaScript Function?

Question

Here is my code:

function pauseSound() {
    var pauseSound = document.getElementById("backgroundMusic");
    pauseSound.pause(); 
}

I would like to add a keyboard shortcut to this code, how can I do this so that the function can also be executed when a button is clicked too?

Tried to add an else if statement but it doesn't work, any ideas?

function doc_keyUp(e) {
    if (e.ctrlKey && e.keyCode == 88) {
        pauseSound();
    }

    else if (e.ctrlKey && e.keyCode == 84) {
        playSound();
    }
}

Answer 1

an event handler for the document's keyup event seems like an appropriate solution

// define a handler
function doc_keyUp(e) {

    // this would test for whichever key is 40 and the ctrl key at the same time
    if (e.ctrlKey && e.keyCode == 40) {
        // call your function to do the thing
        pauseSound();
    }
}
// register the handler 
document.addEventListener('keyup', doc_keyUp, false);