function randomBanner()
{
	var bannerArray = new Array();
	for (var i=1; i<21; i++){
		bannerArray[i-1] = "LI-G-"+i;
		}

	var bannerIndex = Math.round(Math.random()*(bannerArray.length-1));

	if ( document.getElementById("mainFloatContainer").className == "default" )
		document.getElementById("mainFloatContainer").className = bannerArray[bannerIndex];
}