var bannerTime;
function changeBanner()
{
		if(typeof(bannerTime) != "undefined")
			clearTimeout(bannerTime);
		var el =  $("#mainBanner");
		if(arguments.length==0)	
			el.attr("class")=="mainBanner4" ? el.attr("class","mainBanner5"):el.attr("class","mainBanner4");
		else 
			el.attr("class", arguments[0]);
		bannerTime = setTimeout("changeBanner()", 7500);
}
$(document).ready(function() {
	setTimeout("changeBanner()", 7500);	
});