title: Using counter in variable name
body: <p>This is what I have currently but I cant get v(i) to behave the same as v1. What am I doing wrong? 
  I've also tried the piece below which also did not work.</p>
  
  <pre><code>var x = "v" + i;
  alert(x);
  </code></pre>
  
  <p>My main problem is the following:</p>
  
  <pre><code>var v1 = document.getElementById("thing1").innerHTML; // = 100
  var v2 = document.getElementById("thing2").innerHTML; // = 150
  var v3 = document.getElementById("thing3").innerHTML; // = 200
  
  for (i = 0; i &lt; 4; i++) {
      if ( v(i) != ""){
          alert(v(i));
          }
  }
  </code></pre>
  
  <p>Thanks in advance:)</p>