title: Javascript setInterval clearInterval Simple Example Not Working Explained?
body: <p>I have a very simple JS setInterval and clearInterval example that doesn't work.  There has got to be an underlying reason why it does not work and I would like to know why that is:</p>
  
  <pre><code> var automessage;
  
   function turnON() //executed by onclick event A
   {
     var automessage = setInterval(function(){ something() }, 2000);
   }
  
   function turnOff() //executed by onclick event B
   {
     clearInterval(automessage);
   }
  
   function something()
   {
     //pulls instant messages
   }
  </code></pre>
  
  <p>In this example, an end-user clicks a button to start a timed interval process, clicks another button to stop the timed interval process, and then clicks the on button again to start the process again.  Essentially, it would be an on/off styled process.</p>
  
  <p>This doesn't work and I am trying to figure out why.  I can make all of the hundreds of other examples offered on Stackoverflow to work, but I really need an on/off styled process that isn't limited to just on, and then off.  The setInterval should be able to turn on and off at any time.</p>
  
  <p>I really appreciate anyone's help.  Also, I do not use any Jquery libraries.</p>