title: using variable calculated wihin function on itself with setInterval
body: <p>I have a method in my java code that is calculating the current price, i then use this in my javascript code shown below.</p>
  
  <pre><code>function updatePrice(id, currentPrice){
  
  var newPrice = 0;
  var cPrice = currentPrice;
  cPrice = cPrice * 100;
  if(rate == 1){
      newPrice = cPrice - 1;
  }
  if(rate == 2){
  
      newPrice = cPrice - 2;
  }
  if(rate == 3){
  
      newPrice = cPrice - 3;
  }
  document.getElementById(id).innerHTML = newPrice/100;;
  return newPrice / 100;
  }
  
  
  
  var nPrice = updatePrice('reverse', currentPrice); //The new calculated price, currentPrice is the price first injected into the script 
  var timeinterval = setInterval(function() { nPrice = updatePrice('reverse', nPrice); }, 60000); //the nPrice as currentPrice
  </code></pre>
  
  <p>I want to be able to use the newPrice calculated in updatePrice on itself when running setInterval, so that once a minute the newPrice is being used to go down by 1, 2 or 3(pence);</p>
  
  <p>Its probably something quite simple that i just havent noticed yet.</p>
  
  <p>Hopefully this makes sense, fill free to request more info if needed.</p>