i need to construct a circuit to meet the following specifications.

First, a sensor sense the light and it will cut off the motor. Also, i need a latch so that the motor will remain off even the sensor is no longer sensing the light. To be more detailed, the sensor and relay is powered by a 9V battery.


Anyone has idea how to come out with a circuit as to do the above functions..
Thks lots!! Sgchat_03@yahoo.com.sg, u can email me if you know this prob or u got any url regarding this information..

I appreciate much.. thks.