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 ?