dhotel = new Array("./images/topimg3.jpg","./images/topimg4.jpg");
dhotel2 = new Array("./images/topimg_o1.jpg","./images/topimg_o2.jpg");
ohotel = new Array();
for(i=0 ; i<dhotel2.length ; i++){
ohotel[i] = new Image();
ohotel[i].src = dhotel2[i];
}

function ovhotelimg(num){
document.images["menu"+num].src = ohotel[num].src;
}

function ouhotelimg(num){
document.images["menu"+num].src = dhotel[num];
}