Errors :Help required, chat system

filename :VCas3_fla, there are two types of ERORRS in Red5 chat system

ERROR one :
TypeError: Error #1009: Cannot access a property or method of a null object

reference.
at VCas3_fla::MainTimeline/frame1()
Error #2044: Unhandled AsyncErrorEvent:. text=Error #2095: flash.net.NetConnection was unable to invoke

callback onBWDone. error=ReferenceError: Error #1069: Property onBWDone not found on

flash.net.NetConnection and there is no default value.
at VCas3_fla::MainTimeline/frame1()

**ERROR two : **
Error #2044: Unhandled AsyncErrorEvent:. text=Error #2095: flash.net.NetConnection was unable to invoke callback onBWDone. error=ReferenceError: Error #1069: Property onBWDone not found on flash.net.NetConnection and there is no default value.
at VCas3_fla::MainTimeline/frame1()
TypeError: Error #1010: A term is undefined and has no properties.
at VCas3_fla::MainTimeline/onSync2()
null
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at VCas3_fla::MainTimeline/login()