I just found out that my bluetooth couldn't discoverable because it is locked with a little red locker . every time i try to make it discoverable , it said the admind..overide.. and it couldn't change anything. is there anyway to make it discoverable. thank you for your help.

Is it connected to a corporate BES? Sounds like there is an IT policy restricting that.

so what do I have to do with it. I bought it from ebay then unlock it and use it with t-mobile.what do you mean is it connecte to a corporate <<BES>>>?????
and also I just update the newest os. thank you.

It sounds like it was at some time connected to a BES.

Remove IT Policy - BlackBerryFAQ

thank nick its working 100% and removed the little red locker. thank so much.
the only thing that i did just download the policy.bin and follow the step :2,4,5,6,7 and done. rightnow is mine device can be discoverable but still couldn't receive any files that i send from my samsung t509. is it possible the 8700 can recieve any file via bluetooth. thank you.

You need OS 4.2 or Superior. I recommend you for 8700x OS 4.5.

Only go to Media --> Ring/Img ---> ReceiveViaBluetooth

All set, now send files Via You other MobilePhone.