if (key_t == 1)
{
   lights(lights = 0... 1)...
}

Ist natürlich ganz anders aber war eben nicht nur

   lights = 1;

War sogar glaub ich nen Befehl, bin mir aber net sicher...

function setze_licht()
{
  licht = !licht;
}

on_t = setze_licht;

action player_move
{
   var lights = 0;
   player= my;
      while(1)
      ...
         if(key_t == 1)
         {
            Funktion? 
         }
      wait(1);
      }

define lights, skill40;

action player_move
{
  player = my;
  my.lights = 0;
  ...
}

function switch_PlayerLights()
{
  //check if player entity exists
  if(player)
  {
    //switch the lights skill
    player.lights = !player.lights;
  }
}

on_t = switch_PlayerLights;