reporting services erro

Hi All ,
i got some error whn we run the reports in my local system
whn i run the reports in my localhost it display
http://localhost/repots it displays like this
The report server is not responding. Verify that the report server is running and can be accessed from this computer.
Home
whn i run reportserver also i got this error http://localhost/reportserver
Reporting Services Error

• An internal error occurred on the report server. See the error log for more details. (rsInternalError)
  • Object reference not set to an instance of an object.

all sql services are running (reporting also) in my system.
any one pls help me on this issue.
regards
kumar