//Global variables
var elements=null;
var flag=null;

function getElementsByClass(searchClass,node,tag) {
	var classElements = new Array();
	if ( node == null )
		node = document;
	if ( tag == null )
		tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}


function loadAllProducts(){
	elements = getElementsByClass('product');
	var randomNumber=Math.floor(Math.random()*(elements.length));
	if ( randomNumber >=elements.length )	{
		randomNumber =elements.length - 1;
	}
	displayProduct(randomNumber);

}


function displayProduct(index){
	if (elements.length > 0) {
		if(flag != null){
			elements[flag].style.display = 'none';

		}
		flag = index;
		elements[flag].style.display = 'block';
	}
}

function displayNext(){
	var current = flag+1;
	if (current > elements.length-1 )	{
		current = 0;
	}
	displayProduct(current);
}

function displayPrevious(){
	var current = flag-1;
	if (current < 0 )	{
		current = elements.length - 1;
	}
	displayProduct(current);
}