//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageSize(){
	var xScroll, yScroll;
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	var windowWidth, windowHeight;
	if (self.innerHeight) {	// all except Explorer
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	// for small pages with total height less then height of the viewport
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

	// for small pages with total width less then width of the viewport
	if(xScroll < windowWidth){	
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}
	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
}

var timer;

function bodyOverlay() {
	  var objBody = document.getElementsByTagName('body').item(0);
	  var sizesPage = getPageSize();
	  var bodyOverlay = document.createElement("div");
	  bodyOverlay.setAttribute('id','bodyOverlay');
	  bodyOverlay.style.height = arrayPageSize[1] + 'px'; // fundo com o tamanho total da página.
	  if (!document.getElementById('bodyOverlay')) {
		    objBody.insertBefore(bodyOverlay, objBody.firstChild);
	  }
	  /**
	   * Acrescentei isto aqui apenas para chamar a função removerOverlay
	   */
	timer = window.setInterval('removerOverlay()',1000000);
}

function removerOverlay() {
	/**
	 * Acrescentei este alerta apenas para avisar que esta função foi chamada
	 */
	 clearInterval(timer);
	 
	  var bodyOverlay = document.getElementById('bodyOverlay');
	  if (bodyOverlay) {
		    bodyOverlay.parentNode.removeChild(bodyOverlay);
	  }
}