function hovermenu_in(id){
	document.getElementById(id).style.background = "url(img/button_hover.png)";
}
function hovermenu_out(id){
	document.getElementById(id).style.background = "url(img/button_standard.png)";
	
}

function clickmenu(id){
	document.getElementById(id).style.background = "url(img/button_klick.png)";
}