the way i read the original post, exactly that is the requirement. two switches (Sw1 and SW2)

Every led is connected with a tact switch

I read that as a tactile button. In other words a momentary contact switch.

What I'm thinking is a Flip-Flop with LED 1 connected to Q and LED 2 connected to /Q (Not Q). Only one LED will be on at any given time. Then either a single tactile button to clock the FF or one Tac for "Set" and one for "Reset". The problem with this is that you can't lock out one with the other without additional circuitry. I SUPPOSE an "OR" gate can disable the FF once one of the two states (three actually - we forget about both LED's OFF) once one of the two states is activated. Personally I'm not finding a solution. Not that there isn't one, I'm just not seeing it.

But MY question has not yet been addressed:

how do you turn them off?

 

Just hit me - this seems like one of those games where whomever presses their button first lights their light and the person asking the question asks for the answer from the person who first clicked in. Obviously there's a reset to shut everything off. Likely also a master ON / OFF switch.

 

Something like this. AND it has a "Reset" so all lights can be shut off. I still think a master power switch is advisable.

 

From the unclear question, any (momentary or permanent, tact or not tact switch) added/connected in parallel to any led will force-turn that LED off for the duration of the action. [If that was the question...]

 

The LED is only ON while the button is being pressed, no need for a reset.

 

Sorry - got threads confused. REMOVED.

 

The LED is only ON while the button is being pressed, no need for a reset.

Need a clearer understanding of just how the TS wants the project to work. IF the lights go out as soon as the button is released then there's little reason for preventing the other LED from lighting up. IF the light goes on and remains triggered so that the other LED can not be lit then there's going to be a need to be able to shut the LEDs off at some point. Hence, a reset button. NO???

 

I think it's like a game show or voting system. First button pressed and held lights corresponding LED and locks out the other switches.