function setBgimg(){
	var mtstyle = document.getElementById('menutop').style;
	var mbstyle = document.getElementById('menubottom').style;
	mtstyle.background = 'no-repeat url(' + getBgimg(0) + ')';
	mbstyle.background = 'no-repeat url(' + getBgimg(1) + ')';
}
function getBgimg(torb){
	var bgTList = new Array('menu-top.png','menu-top2.png','menu-top3.png','menu-top4.png','menu-top5.png');
	var bgBList = new Array('menu-bottom.png','menu-bottom2.png','menu-bottom4.png','menu-bottom5.png');
	if(torb == 0){
		var r = Math.floor(Math.random() * bgTList.length); 
		var bgimg = 'images/' + bgTList[r];
		return bgimg;
	}
	else if(torb == 1){
		var r = Math.floor(Math.random() * bgBList.length); 
		var bgimg = 'images/' + bgBList[r];
		return bgimg;
	}
}