function killEverybody(%start){
%start = %start ? %start : 0; // if %start isn't defined, use 0
%player = ClientGroup.getObject(%start).player; // get the player at position %start in ClientGroup
if(isObject(%player)) // if the player exists (is spawned)
%player.kill(); // kill them
%start++; // increment start
if(ClientGroup.getCount() > %start) // if there are more people left
schedule(3000, 0, "killEverybody", %start); // schedule this function to be called again in 3 seconds with the new %start value
}