function openRegistration(){
	
	var registration = document.getElementById('registration');
	var registrationBox = document.getElementById('registration_box');
	
	var arrayPageSize = this.getPageSize();
	$('registration').setStyle({ width: arrayPageSize[0] + 'px', height: arrayPageSize[1] + 'px' });
	
	var arrayPageScroll = document.viewport.getScrollOffsets();
	var registrationBoxTopBase = (document.viewport.getHeight() / 2) - 175;
	var registrationBoxLeftBase = (document.viewport.getWidth() / 2) - 300;
	var registrationBoxTop = arrayPageScroll[1] + registrationBoxTopBase;
	var registrationBoxLeft = arrayPageScroll[0] + registrationBoxLeftBase;
	$('registration_box').setStyle({ top: registrationBoxTop + 'px', left: registrationBoxLeft + 'px' });
	
	new Effect.Appear(registration, { duration: .5, from: 0.0, to: 0.8 });
	new Effect.Appear(registrationBox, { delay: 1});
}

function closeRegistration(){
	
	var registration = document.getElementById('registration');
	var registrationBox = document.getElementById('registration_box');
	
	new Effect.Fade(registration, { duration: .5});
	new Effect.Fade(registrationBox, { duration: .5});
	
	document.getElementById('firstname').value = '';
	document.getElementById('lastname').value = '';
	document.getElementById('email').value = '';
	
}

function registrationSubmit(){
	document.getElementById('registration_info').submit();
}

function getPageSize() {
        
     var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = window.innerWidth + window.scrollMaxX;
		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
		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];
}