javax.bluetooth.BluetoothExeption: unable to swithc master

[mahdi68]

Hi
i want to write bluetooth base app for send and recive string between two device . i have problem . i send string from device A and device B recive it but when i try to send answer from device B to A i get this notifier :
javax.bluetooth.BluetoothExeption: unable to swithc master
it is becouse this part of code :StreamConnection conn =(StreamConnection) Connector.open(connString);
now what should i do for slove this probleam ?
thanks