players kills

How can I see if a player has gotten X amount of kills in 3 seconds?

My buddy told me to do something like this
[lua]local times = {}
times[1] = CurTime() [/lua]
and if it returns 5, then it’s 5 second or something like that. I get what he’s saying but I’m not exactly sure how to do what he is saying. Can anyone help?

taken from hackvshack:
[lua]
local kills = attacker:IsPlayer() && attacker:Frags() || false
timer.Simple( 1, function()
if( kills && attacker ) then
if( attacker:Frags() - kills >= 3 ) then
PrintMessage( HUD_PRINTCENTER, string.upper( attacker:Nick() ) … " MONSTER KILL" )
umsg.Start(“hvhsound”)
umsg.String(“hvh/monsterkill.mp3”)
umsg.End()
end
end
end )
[/lua]

<3