masukkan tiga batang dalam php yang digunakan untuk meminimalkan dan memaksimalkan halaman

<!DOCTYPE html>
<html>
<head>
  <title></title>
  <script language="javascript" type="text/javascript">

function toggleFullScreen() {
  if (!document.fullscreenElement &&    // alternative standard method
      !document.mozFullScreenElement && !document.webkitFullscreenElement && !document.msFullscreenElement ) {  // current working methods
    if (document.documentElement.requestFullscreen) {
      document.documentElement.requestFullscreen();
    } else if (document.documentElement.msRequestFullscreen) {
      document.documentElement.msRequestFullscreen();
    } else if (document.documentElement.mozRequestFullScreen) {
      document.documentElement.mozRequestFullScreen();
    } else if (document.documentElement.webkitRequestFullscreen) {
      document.documentElement.webkitRequestFullscreen(Element.ALLOW_KEYBOARD_INPUT);
    }
  } else {
    if (document.exitFullscreen) {
      document.exitFullscreen();
    } else if (document.msExitFullscreen) {
      document.msExitFullscreen();
    } else if (document.mozCancelFullScreen) {
      document.mozCancelFullScreen();
    } else if (document.webkitExitFullscreen) {
      document.webkitExitFullscreen();
    }
  }
}

document.addEventListener("fullscreenchange", function () {
    fullscreenState.innerHTML = (document.fullscreen)? "on" : "not ";
}, false);

document.addEventListener("mozfullscreenchange", function () {
    fullscreenState.innerHTML = (document.mozFullScreen)? "on" : "not ";
}, false);

document.addEventListener("webkitfullscreenchange", function () {
    fullscreenState.innerHTML = (document.webkitIsFullScreen)? "on" : "not ";
}, false);

document.addEventListener("msfullscreenchange", function () {
    fullscreenState.innerHTML = (document.msFullscreenElement)? "on" : "not ";
}, false);
</script>
</head>
<body>
<a href="javascript:void(0);" onclick="toggleFullScreen();">
Open in Full Screen Window</a>
<p>Fullscreen state: I'm <b id="fullscreenState"> not </b> fullscreen</p>
</body>
</html>
clara kg