Browser tab visibility control

tabChange

var eventName = "visibilitychange";
if (document.webkitHidden != undefined) {
    eventName = "webkitvisibilitychange";
} else if (document.mozHidden != undefined) {
    eventName = "mozvisibilitychange";
} else if (document.msHidden != undefined) {
    eventName = "msvisibilitychange";
} else if (document.hidden != undefined) {

} else {

}

function visibilityChanged() {
  if (document.hidden || document.mozHidden || document.msHidden || document.webkitHidden) {
      /* tab invisible */
  } else {
      /* tab visible */
  }
}

document.addEventListener(eventName, visibilityChanged, false);