Android video issue (First video get frozen when i play 2nd)

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http://stackoverflow.com – I am working on an android based application, that play videos. when i play any video it starts it then i press the back button and go to back screen to select another one to play(with-out stopping the first video) when i select the second video the first video (that was already playing) get frozen and second video get started behind this first video, i can listen the music etc of the second video, can any one help how that how to stop and remove the video from media player so that user may watch the new video Here is my activity public class TrailVideoActivity extends Activity implements (HowTos)