Help!!! External Hard Disk Corrupted and Unreadable

Hi,

I’m using 80GB external hard disk for my study used… When i brought it to my Uni’s computer lap today, it was hang and without accesible. It shown the message “the file and directory is corrupted and unreadable”, could you please let me know what’s the matter with my hard disk? I don’t have any backup, it’s so awful for me to lost those information which store in my hard disk…. please… i need help….