title: check multiple input fields with one variable
body: <p>I have a lot input boxes and I need to make a condition that checks if all of them are empty how can I do this in javascript with a single variable. This is what I have, but it only checks 1 box</p>
  
  <pre><code>function boxes() {
  
      var box_a = document.getElementById('box_a');
  
           if(box_a==="")   {
              alert("box not filled")
                 return false;
            } 
  
   &lt;input type="text" id="box_a"&gt;
  </code></pre>