// -----------------------------------------------------------------------------------

function o(who) {
	return document.getElementById(who);
}

// -----------------------------------------------------------------------------------

// stretch overlay to fill page and fade in
function mostraOverlay() {
	var arrayPageSize = getPageSize();
	setHeight('overlay', arrayPageSize[1]);
	exampleFx = new Fx.Style('overlay', 'opacity', {
		duration: 400, 
		transition: Fx.Transitions.quartInOut
	});
	exampleFx.start(0,0.8);
}

// -----------------------------------------------------------------------------------

// fade overlay out
function nascondiOverlay() {
	exampleFx = new Fx.Style('overlay', 'opacity', {
		duration: 400, 
		transition: Fx.Transitions.quartInOut
	});
	exampleFx.start(0.8,0);
}


// -----------------------------------------------------------------------------------
function setHeight(el, h) {
	o(el).style.height = h +"px";
}

//
// 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) 
	return arrayPageSize;
}