My external hardisk is not working

Hello,



hey guys i have storejet 320GB External Hard disk..
n wen i plug it in to my computer it make the sound when i plug it btw i cant. get read of any of my dat in my hard disk
and i tried to scan it..n it cant scan even...n i give a right click on my hardisk drive n properties..its juss showing 0 bytes.. but ..its 320 GB..n i have around 210 GB data on dat hardisk..
do cud some one please help in this case..
id reali need to get my data's back