how to start broadcasting

When user first time log into site camera start the capturing and stream is saved in application folder with the streamname(straemname.flv). then user logout and then logged in then i have to append that stream in same straemname.flv file .By this code i have done that task

camera = Camera.getCamera();

camera.setQuality(0,80);  
camera.setMode(videoWidth,videoheight,15,true);
camera.setLoopback(false);

video.attachCamera(camera);
ns.attachCamera(camera);
ns.publish(stream, "append");     

But i am facing the problem when user again logged in ,the video which is saved previously start playing,I dont want start that video.I just want to show camera control

How to solve that issue.