// JavaScript Document

var DEFAULT_MAX_ITEMS = 4;

function randomizeTop()
{
	var container = document.getElementById('preview');	
	if(!container) 
	{ 
		//alert('container does not exist');
		return; 
	} 
	
	var spanList = container.getElementsByTagName('span');
	if(!spanList) 
	{ 
		//alert('spanList does not exist');
		return; 
	} 
	
	var maxItems = MAX_ITEMS || DEFAULT_MAX_ITEMS;
	var usedItems = [];
	
	var len = spanList.length;
	for(var i=0; i<maxItems && i<len; i++)
	{
		var rnd = Math.floor(Math.random() * len);
		if(usedItems[rnd])
		{
			// pick another number, this one is already shown
			i--;
		}
		else
		{
			spanList[rnd].style.display = 'block';
			usedItems[rnd] = 1;
		}
	}
}

flexOnloadRegister('randomizeTop()');