title: Any way to simplify this code?
body: <p>New to javascript! This works, but I have a lot more to do, and it would be great if there was a cleaner way to do this.. open to using jquery if neccesary :)</p>
  
  <p>(stack wants me to write more before I submit, though I'm not sure what else to say)</p>
  
  <pre><code>&lt;script&gt;
  
  function apply(){
      var backerPrediction1 = document.getElementById("backer-prediction-1").value;
      var backerPrediction2 = document.getElementById("backer-prediction-2").value;
      var backerPrediction3 = document.getElementById("backer-prediction-3").value;
      var backerPrediction4 = document.getElementById("backer-prediction-4").value;
      var backerPrediction5 = document.getElementById("backer-prediction-5").value;
      var backerPrediction6 = document.getElementById("backer-prediction-6").value;
      var backerPrediction7 = document.getElementById("backer-prediction-7").value;
      var backerPrediction8 = document.getElementById("backer-prediction-8").value;
      var backerPrediction9 = document.getElementById("backer-prediction-9").value;
      var backerPrediction10 = document.getElementById("backer-prediction-10").value;
      var backerPrediction11 = document.getElementById("backer-prediction-11").value;
      var backerPrediction12= document.getElementById("backer-prediction-12").value;
      var backerPrediction13 = document.getElementById("backer-prediction-13").value;
      var backerPrediction14 = document.getElementById("backer-prediction-14").value;
      var backerPrediction15 = document.getElementById("backer-prediction-15").value;
      var backerPrediction16 = document.getElementById("backer-prediction-16").value;
      var backerPrediction17 = document.getElementById("backer-prediction-17").value;
      var backerPrediction18 = document.getElementById("backer-prediction-18").value;
      var backerPrediction19 = document.getElementById("backer-prediction-19").value;
      var backers = parseInt(backerPrediction1,10) +
                parseInt(backerPrediction2,10) +
                parseInt(backerPrediction3,10) +
                parseInt(backerPrediction4,10) +
                parseInt(backerPrediction5,10) +
                parseInt(backerPrediction6,10) +
                parseInt(backerPrediction7,10) +
                parseInt(backerPrediction8,10) +
                parseInt(backerPrediction9,10) +
                parseInt(backerPrediction10,10) +
                parseInt(backerPrediction11,10) +
                parseInt(backerPrediction12,10) +
                parseInt(backerPrediction13,10) +
                parseInt(backerPrediction14,10) +
                parseInt(backerPrediction15,10) +
                parseInt(backerPrediction16,10) +
                parseInt(backerPrediction17,10) +
                parseInt(backerPrediction18,10) +
                parseInt(backerPrediction19,10)
  ;
  document.getElementById("backer-prediction-answer").value = (backers);
  }
  &lt;/script&gt;
  </code></pre>
  
  <p>Thanks for your help!! :)</p>