function PreloadImages(length, path, type) {
   for(var i = 1; i<=length; i++) {
       this[i]= new Image()
       this[i].src= path + i + type
   }
   return this
}



function rollon(num) {
if(document.images){
	eval('document.images["menu'+num+'"].src='+'on[num].src');}
  }

function rolloff(num) {
if(document.images){
				eval('document.images["menu'+num+'"].src='+'off[num].src');}
 else{ alert('no images!');}
  }


  off = new PreloadImages(10,'/images/menu_','.gif');
on = new PreloadImages(10,'/images/onmenu_','.gif');
real_off =  off;
real_on =  on;