title: Cannot change value with a timer
body: <p>I'm reporting issues when I try to change a variable value with a timer.</p>
  
  <p>Actually I'm using the following code to perform that:</p>
  
  <pre><code>local counter = math.random(100, 350)
  local function changeCounterValue()
      counter = math.random(130, 170)
  end
  tmr = timer.performWithDelay(1500, changeCounterValue, 0)
  </code></pre>
  
  <p>but it just doesn't work?</p>