A location-based and preference-based system and method for matching information such as the attributes, interests andor characteristics profiles of persons with the expressed preferences of mobile users to alert and direct such users to any persons having information matching the user’s express preferences. A piston located in the fluid chamber divides the fluid chamber into first and second regions. The player can continue playing regardless of whether the balance is less than zero. According to the invention, seen from the radiation source towards the beam exit window, the first and the second optical axis coincide starting at a position between the radiation source and the beam manipulator.