function start() {
var north = true;
var backImg = ['backgM_summer.JPG','backgM_fall4.jpg','backgM_winter.JPG','backgM_spring.JPG'];
var today = new Date();
var month = today.getMonth();
if (today.getDate() > 10) month++;
document.getElementById('seasonal').style.backgroundImage = 'url('+backImg[Math.floor((month+(north?6:0))/3)%4]+')';
}

var pageLoaded = 0;
window.onload = function() {pageLoaded = 1;}
function loaded(i,f) {
if (document.getElementById && document.getElementById(i) != null) f();
else if (!pageLoaded) setTimeout('loaded(\''+i+'\','+f+')',100);
}
loaded('seasonal',start);