//Essa função pega a altura e a largura da pagina toda, mesmo com barra de rolagem.
function getPageSize() {
		
	 var xScroll, yScroll;
	
	if (document.innerHeight && document.scrollMaxY) {	
		xScroll = document.innerWidth + document.scrollMaxX;
		yScroll = document.innerHeight + document.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
		if(document.documentElement.clientWidth){
			windowWidth = document.documentElement.clientWidth; 
		} else {
			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 = xScroll;		
	} else {
		pageWidth = windowWidth;
	}

	return [pageWidth,pageHeight];
}

// pega a altura e a largura da área de utilização do browser
function larguraAlturaAreaUtilizavelDoBrowser() {
	var myWidth = 0, myHeight = 0;
	if( typeof( window.innerWidth ) == 'number' ) {
		//não é IE
		myWidth = window.innerWidth;
		myHeight = window.innerHeight;
	} else if (document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight)) {
		//IE 6+ em modo 'standards compliant'
		myWidth = document.documentElement.clientWidth;
		myHeight = document.documentElement.clientHeight;
	} else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
		//IE 4
		myWidth = document.body.clientWidth;
		myHeight = document.body.clientHeight;
	} else { // pega a resolução da tela, se não foi possível encontrar acima
		myHeight = window.screen.availHeight;
		myWidth = window.screen.availWidth;
	}

//	alert( 'Width = ' + myWidth );
//	alert( 'Height = ' + myHeight );

	return [myWidth,myHeight];
}