menuentry "Ubuntu 13.04 ISO" {
set isofile="/home/xubuntu/Downloads/xubuntu-13.04-desktop-amd64.iso"
loopback loop (hd1,2)$isofile
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile noprompt noeject
initrd (loop)/casper/initrd.lz
}