hi every one

i am a new bb user,the problem im having is when i connect to the usb the screen goes white and nothing happens,when i first connected it to usb the red light stayed on and nothing happened,now i just get the white screen,also i only have the usb cable for chargeing and i only have
1 bar of battery left so PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.......i just connected the usb again and now i there is nothing no white screen then when i disconnected usb the phone turned itself on .............HELP.............