There was an answer in your other topic, I'll post it here;
Every tick
add dt to reload
Reload >= 1
plane shoot bullet
set reload to 0
dt is just "dt". You can see it under system expressions.
DT, or delta time, is the time between every tick.
Basically, this will shoot something every 1 second. If you want it to shoot
every 2 seconds, set it to 2. Every half second? 0.5.
You want to do it this way so your game is framerate independent.
It's important, since you want your game to run the same at all
framerates.
You can read more about delta time and framerate independence here.
EDIT: I made a capx for you, check it out here.