Place push buttons behind the jacks and make sure buttons triggering when plug the male jacks, then use hot glue to fix the buttons. these buttons for sensing if jack is plugged in.
http://img190.imagevenue.com/img.php?image=346235306_IMG_1358_resize_122_416lo.JPG
http://img159.imagevenue.com/img.php?image=346242699_IMG_1359_resize_122_408lo.JPG
http://img141.imagevenue.com/img.php?image=346250825_IMG_1360_resize_122_49lo.JPG
http://img103.imagevenue.com/img.php?image=346257996_IMG_1362_resize_122_1075lo.JPG
remove these two pcb tracks.
solder 1K resistor between pin2 and pin4 of audio header