// Global variable
var currentBanner = 0;

function countBanners(){
	// Find all items
	var banners = document.getElementsByTagName('DIV');
	var bannersNum = banners.length;
	var bannersCount=0;
	var t;
	
	for(t=0;t<bannersNum;t+=1){
		if(banners[t].className=='random-area'){
			bannersCount+=1;
		}
	}
	
	return bannersCount;
}

function switchBanners(){
	// Get the number of banners
	var count = countBanners();
	
	if(count>5){
		// Hide all banners (with exception)
		nextBanners = currentBanner + 1;
		nextBannersRow = nextBanners + 4;
		
		hideBanners(nextBanners,nextBannersRow,count);
	
		// Repeat function
		var timer = setTimeout("switchBanners()", 7000);
	}
}

function hideBanners(nextBanner,nextBannerRow,countBanner){
	for(var i=1;i<=countBanner;i+=1){
		// Show the banners between nextBanner and nextBannerRow, hide the rest
		if(i>=nextBanner && i<=nextBannerRow){
			document.getElementById('o_banner_'+i).style.display = 'block';
		}else{
			document.getElementById('o_banner_'+i).style.display = 'none';
		}
	}
	
	// Update counter
	if(nextBannerRow==countBanner){
		currentBanner = 0;
	}else{
		currentBanner+=1;
	}
}

var SponsorNumber=undefined;
function ShowNextSponsor() {
	if ( typeof(SponsorNumber)=='undefined' ) {
		SponsorNumber=1;
		var elm=document.getElementById('random'+SponsorNumber);
		while ( elm ) {
			if ( elm.style.display!='none' ) break;
			SponsorNumber+=1;
			elm=document.getElementById('random'+SponsorNumber);
		}
	}
	// alert("SponsorNumber="+SponsorNumber + ", Type: "+typeof(document.getElementById('Sponsor'+SponsorNumber)));
	//alert("Tag: "+document.getElementById('Sponsor'+SponsorNumber).id);
	document.getElementById('random'+SponsorNumber).style.display='none';
	
	SponsorNumber+=1;
	if ( !document.getElementById('random'+SponsorNumber) ) SponsorNumber=1;
	document.getElementById('random'+SponsorNumber).style.display='block';
	setTimeout("ShowNextSponsor()", 5000);
}