HTML5 video custom controls

Question

I'm trying to add some custom controls to my html 5 video but having issues getting it to work.

I need to add a toggle button Pause and Play. This is part of my code and the error I'm getting is Uncaught TypeError: Cannot set property 'title' of null

var billboardC, video, playpause;
var videoBGPlayer;

function init(){

    billboardC = document.getElementById('billboardC');

    video = document.getElementById('video-player');
    playpause = document.getElementById('playpause');
}


function OpenVideo(e){
    console.log('open video');
    billboardC.innerHTML += "<div class='closeButton'></div>";
    billboardC.innerHTML += "<a href='www.google.com' target='blank'     class='fombutton'>Find Out More</a>";
    billboardC.style.visibility = 'visible';
    billboardC.innerHTML += "<video id='video-player'     class='videoSquare' poster='' muted> <source src='my-video.mp4'     type='video/mp4' /></video><div id='controls'><button id='playpause'      onclick='togglePlayPause()' title='play'>Play</button></div>";

}

function togglePlayPause() {
    if (video.paused || video.ended) {
      playpause.title = "pause";
      playpause.innerHTML = "pause";
      video.play();
      console.log('play');
   }
   else {
      playpause.title = "play";
      playpause.innerHTML = "play";
      video.pause();
      console.log('pause');
   }
}


window.onload = function(){ init(); }

Thanks

Answer 1

Detailed descriptions are in the comments within the Snippet.

SNIPPET

 var billboardC = document.getElementById('billboardC'); var videoBGPlayer; /* The variables that were within init() were not accessible by other functions. Normally you would just place the variables outside to become global and accessible. But all of the elements do not exist until OpenVideo() is finished parsing them, so the variables are undefined. In order to create useful references, I placed the needed variables within togglePlayPause(). */ /* OpenVideo() was never invoked, therefore no HTML, no dice. So I placed OpenVideo within init() so it would be the first function (besides init() of course to be invoked. */ function init(){ OpenVideo(); } function OpenVideo(){ console.log('open video'); billboardC.innerHTML += "<div class='closeButton'></div>"; billboardC.innerHTML += "<a href='www.google.com' target='_blank' class='formbutton'>Find Out More</a>"; billboardC.style.visibility = 'visible'; billboardC.innerHTML += "<video id='video-player' class='videoSquare' poster='' muted> <source src='my-video.mp4' type='video/mp4'></video><div id='controls'><button id='playpause' onclick='togglePlayPause()' title='play'>Play</button></div>"; } function togglePlayPause() { var video = document.getElementById('video-player'); var playpause = document.getElementById('playpause'); if (video.paused || video.ended) { playpause.title = "pause"; playpause.innerHTML = "pause"; video.play(); console.log('play'); } else { playpause.title = "play"; playpause.innerHTML = "play"; video.pause(); console.log('pause'); } } /* When using window.onload = foo; do not use the functions parenthesis `()`. If you leave out the paranthesis, that will tell the renderer that it is up to it to decide when init should execute. */ window.onload = init;

 <!--#billboardC didn't exsist and it wasn't included in OpenVideo()--> <main id="billboardC"></main>