HTML - crear boton maximizar

<button onclick="openFullscreen()">Test Fullscreen</button>

<h4>Presiona "Esc" para salir de Fullscreen.</h4>

<h2 id="test" style="padding:48px;border:4px solid;color:#44DDDD">Test Fullscreen . . .</h2>

<script>

var element = document.getElementById("test");

function openFullscreen() {

var requestMethod = element.webkitRequestFullScreen || element.mozRequestFullScreen || element.msRequestFullScreen || element.requestFullScreen;

if (requestMethod) {requestMethod.call(element)}

else

if (typeof window.ActiveXObject !== "undefined") {

var wscript = new ActiveXObject("WScript.Shell");

if (wscript !== null) {wscript.SendKeys("{F11}")}

}

}

</script>