Gstream stop

[Vishva]

Hi,
i am using QT to stream video from CAM using gstream. when i give gst-lauch source, i am able to see the streaming... but i am not able to stop the same. I have to give ctrl+c to stop the streaming. is there an alternate to this??
with a button press i need to stop the streaming!!!!!
is it possible??
Kindly advice...