var LastSeconds = -1;

function LoadBanner()
{
	var theBanner;
	var StartDate = new Date();
	var Seconds = StartDate.getMinutes() * 2;
	var theURL;
	
	theBanner = document.getElementById("banner");
	do{
		Seconds = Math.floor(Seconds/2);
		if( Seconds == LastSeconds )
		{
			return;
		}
		theURL = "http://davidcrowe.ca/banner/" + Seconds.toString() + ".jpg";
	}while( !isThere(theURL) && Seconds > 0)

	banner.src = theURL;
	LastSeconds = Seconds;
}

function isThere(url)
{
	var req = new XMLHttpRequest();
	try{
		req.open("HEAD",url,false);
		req.send(null);
		return (req.status == 200)
	}
	catch(er){
		return(false);
	}
}