title: I want lua function to run once
body: <p>I'm quite new to lua scripting.. now i'm trying to code in game boss</p>
  
  <pre><code>local function SlitherEvents(event, creature, attacker, damage)
      if(creature:GetHealthPct() &lt;= 60) then
          creature:SendUnitYell("Will punish you all",0)
          creature:RegisterEvent(AirBurst, 1000, 0) -- 1 seconds
          return
      end
  end
  </code></pre>
  
  <p>this should make the boss talk when his health = 60% or less but it should  run one time, when I run the code the boss keep saying and attacking all the time. How can I make it run once?</p>