fullscreen_api.js

/* Request Fullscreen on spesific element */
  function requestFullScreen(element) {
    // Supports most browsers and their versions.
    var requestMethod = element.requestFullScreen || element.webkitRequestFullScreen || element.mozRequestFullScreen || element.msRequestFullScreen;
    if (requestMethod) { // Native full screen.
      requestMethod.call(element);
    } else if (typeof window.ActiveXObject !== "undefined") { // Older IE.
      var wscript = new ActiveXObject("WScript.Shell");
      if (wscript !== null) {
        wscript.SendKeys("{F11}");
      }
    }
  }
  
/* Request Fullscreen Global */
  function toggleFullScreen() {
    if ((document.fullScreenElement && document.fullScreenElement !== null) || (!document.mozFullScreen && !document.webkitIsFullScreen)) {
      if (document.documentElement.requestFullScreen) {
        document.documentElement.requestFullScreen();  
      } else if (document.documentElement.mozRequestFullScreen) {  
        document.documentElement.mozRequestFullScreen();  
      } else if (document.documentElement.webkitRequestFullScreen) {  
        document.documentElement.webkitRequestFullScreen(Element.ALLOW_KEYBOARD_INPUT);  
      }
    } else {
      if (document.cancelFullScreen) {  
        document.cancelFullScreen();  
      } else if (document.mozCancelFullScreen) {  
        document.mozCancelFullScreen();  
      } else if (document.webkitCancelFullScreen) {  
        document.webkitCancelFullScreen();  
      }  
    }  
  }

// Usage on spesific element
<input type="button" value="click to go fullscreen" onclick="requestFullScreen(document.body)">
// Usage as global
<input type="button" value="click to go fullscreen" onclick="toggleFullScreen()">