Interactive Example , Mouse Lock (Pointer Lock) i chrome

<button onclick="lockPointer();" id='lockButton'>Lås musen</button>
<div id="pointer-lock-element"></div>
<script>
// Note: at the time of writing, only Mozilla and WebKit support Pointer Lock.

// The element we'll make fullscreen and pointer locked.
var elem;

document.addEventListener("mousemove", function(e) {
if (elem != null) {
  var movementX = e.movementX       ||
                  e.mozMovementX    ||
                  e.webkitMovementX ||
                  0,
      movementY = e.movementY       ||
                  e.mozMovementY    ||
                  e.webkitMovementY ||
                  0;

  // Print the mouse movement delta values
  document.getElementById('lockButton').innerHTML = "movementX=" + movementX +" - movementY=" + movementY;
  }
}, false);

function pointerLockChange() {
  if (document.mozPointerLockElement === elem ||
      document.webkitPointerLockElement === elem) {
    //console.log("Pointer Lock was successful.");
  } else {
	elem = null;
	document.getElementById('lockButton').innerHTML = "Lås musen";
  }
}

document.addEventListener('pointerlockchange', pointerLockChange, false);
document.addEventListener('mozpointerlockchange', pointerLockChange, false);
document.addEventListener('webkitpointerlockchange', pointerLockChange, false);

function lockPointer() {
  elem = document.getElementById("pointer-lock-element");
  elem.requestPointerLock = elem.requestPointerLock    ||
                              elem.mozRequestPointerLock ||
                              elem.webkitRequestPointerLock;
    elem.requestPointerLock();
}
</script>

<button onclick="lockPointer();">Lock it!</button>
<div id="pointer-lock-element" style="background:#ccc;">
	<div id="coords" style="background:#666;display:none;color: #ffff00;">
	</div>
</div>
<script>
// Note: at the time of writing, only Mozilla and WebKit support Pointer Lock.

// The element we'll make fullscreen and pointer locked.
var elem;

document.addEventListener("mousemove", function(e) {
if (elem != null) { //NY
  var movementX = e.movementX       ||
                  e.mozMovementX    ||
                  e.webkitMovementX ||
                  0,
      movementY = e.movementY       ||
                  e.mozMovementY    ||
                  e.webkitMovementY ||
                  0;

  // Print the mouse movement delta values
  document.getElementById('coords').innerHTML = "movementX=" + movementX + " - movementY=" + movementY;
  } //NY
}, false);

function fullscreenChange() {
  if (document.webkitFullscreenElement === elem ||
      document.mozFullscreenElement === elem ||
      document.mozFullScreenElement === elem) { // Older API upper case 'S'.
    // Element is fullscreen, now we can request pointer lock
    elem.requestPointerLock = elem.requestPointerLock    ||
                              elem.mozRequestPointerLock ||
                              elem.webkitRequestPointerLock;
    elem.requestPointerLock();
  }
}

document.addEventListener('fullscreenchange', fullscreenChange, false);
document.addEventListener('mozfullscreenchange', fullscreenChange, false);
document.addEventListener('webkitfullscreenchange', fullscreenChange, false);

function pointerLockChange() {
  if (document.mozPointerLockElement === elem ||
      document.webkitPointerLockElement === elem) {
    console.log("Pointer Lock was successful.");
	document.getElementById('coords').style.display = 'block'; //NY
  } else {
    console.log("Pointer Lock was lost.");
	document.getElementById('coords').style.display = 'none'; //NY
  }
}

document.addEventListener('pointerlockchange', pointerLockChange, false);
document.addEventListener('mozpointerlockchange', pointerLockChange, false);
document.addEventListener('webkitpointerlockchange', pointerLockChange, false);

function pointerLockError() {
  console.log("Error while locking pointer.");
}

document.addEventListener('pointerlockerror', pointerLockError, false);
document.addEventListener('mozpointerlockerror', pointerLockError, false);
document.addEventListener('webkitpointerlockerror', pointerLockError, false);

function lockPointer() {
  elem = document.getElementById("pointer-lock-element");
  // Start by going fullscreen with the element.  Current implementations
  // require the element to be in fullscreen before requesting pointer
  // lock--something that will likely change in the future.
  elem.requestFullscreen = elem.requestFullscreen    ||
                           elem.mozRequestFullscreen ||
                           elem.mozRequestFullScreen || // Older API upper case 'S'.
                           elem.webkitRequestFullscreen;
  elem.requestFullscreen();
}
</script>