window.onload = initLinks;

function initLinks() {
	document.getElementById("season").onmouseover = processSwap;
}

function processSwap() {
if (document.getElementById("mainleft").style.background.indexOf('left_2') != -1) {
document.getElementById("mainleft").style.background = 'url(images/image_left_1.jpg)'
}
else {
document.getElementById("mainleft").style.background =  'url(images/image_left_2.jpg)'
}
if (document.getElementById("mainmid").style.background.indexOf('mid_2') != -1) {
document.getElementById("mainmid").style.background = 'url(images/image_mid_1.jpg)'
}
else {
document.getElementById("mainmid").style.background =  'url(images/image_mid_2.jpg)'
}
if (document.getElementById("mainright").style.background.indexOf('right_2') != -1) {
document.getElementById("mainright").style.background = 'url(images/image_right_1.jpg)'
}
else {
document.getElementById("mainright").style.background =  'url(images/image_right_2.jpg)'
}
if (document.getElementById("season").src.indexOf('summer') != -1) {
document.getElementById("season").src =  "images/winter.gif"
}
else {
document.getElementById("season").src =  "images/summer.gif"
}
}