title: show more info when click a button html, css, javascript
body: <p>I have written a code where i have one box and when i click the button it actually shows more or less info. See it in action here: <a href="https://jsfiddle.net/075tcezL/" rel="nofollow noreferrer">https://jsfiddle.net/075tcezL/</a></p>
  
  <pre><code>/css
  #model {
  width: 300px;
  border: 1px solid #c1c1c1;
  margin: 20px 10px;
  padding: 0 5px;
  float: left;
  max-height: 300px;
  overflow: hidden;
  
  
  -webkit-transition: max-height 0.7s;
  -moz-transition: max-height 0.7s;
  transition: max-heigth 0.7s;
  
  }
  #show-more {
  display: block;
  background-color: #75868E;
  width: 100px;
  font-size: 12px;
  text-transform: uppercase;
  display: inline-block;
  margin: 20px auto;
  cursor: pointer;
  height: 15px;
  padding: 10px 0; 
  }
  
  #model.open {
  max-height: 1000px;
  
  -webkit-transition: max-heigth 0.7s;
  -moz-transition: max-heigth 0.7s;
  transition: max-heigth 0.7s;
  }
  </code></pre>
  
  <p>//HTML</p>
  
  <pre><code>&lt;body&gt;
  &lt;div id="model" class="model1"&gt;
      &lt;h3&gt;Series 3&lt;/h3&gt;
          &lt;a href="#series3" id="sseries"&gt;&lt;img class="image" 
              src="image"&gt;&lt;/a&gt;
  
  &lt;p&gt;Text to hide or show.&lt;/p&gt;
  
  &lt;/div&gt;                      
  &lt;a id="show-more" class="show"&gt;Show More&lt;/a&gt;
  
  &lt;script src="javascript.js"&gt;&lt;/script&gt;
  
  &lt;/body&gt;
  </code></pre>
  
  <p>//This works with one box</p>
  
  <pre><code>var content = document.getElementById("model");
  var button = document.getElementById("show-more")
  
  button.onclick = function(){
  
  if(content.className == "open"){
      content.className = "";
      button.innerHTML = "More";
  
  } else {
      content.className = "open";
      button.innerHTML = "Less";
  }
  
  };
  </code></pre>
  
  <p>But if i have three boxes, like this - <a href="https://jsfiddle.net/jw7pfb1w/" rel="nofollow noreferrer">https://jsfiddle.net/jw7pfb1w/</a>
  How do i open or close them at the same time when clicking on that button?</p>
  
  <p>Any help would be appreciated!</p>