SanDisk cruzer blade 16GB not recognising...

Hello,
I hav a sandisk cruzer blade 16 gb thumbdrive,i don knw suddenly wht ahappened to it,now its not at being recognised on my system or elswhere..pls help me as I hav lot of data on it...i m even unable to formate it bcz whn I press right click n press on format it wont take the comand at alll.. its not taking any command, in if plugin into USB it shows as "removable disc" but not with name whn I click on properties it does not show availbale space n says this device is working properly..
Pls help me to atleast format it show that I can use it further...