function submenuOver(button) {
	button.style.backgroundImage = "url(images/submenu_bghigh-winter.gif)";
}
		
function submenuOut(button){
	button.style.backgroundImage = "url(images/submenu_bglow-winter.gif)";
}

function submenuPageOver(button) {
	button.style.backgroundImage = "url(images/submenu_bgpage.gif)";
}
		
function submenuPageOut(button){
	button.style.backgroundImage = "url(images/space.gif)";
}

function winterOver(){
	document.getElementById("button-winter").style.backgroundImage = "url(images/space.gif)";
	document.getElementById("button-sommer").style.backgroundImage = "url(images/bg-buttonsommer.gif)";
}

function sommerOver(){
	document.getElementById("button-sommer").style.backgroundImage = "url(images/space.gif)";
	document.getElementById("button-winter").style.backgroundImage = "url(images/bg-buttonwinter.gif)";
}