title: plus width of div in DOM
body: <p>i have sample div (width: 10%) and a sample button, i want when click on the button, div's width plus with 10.</p>
  
  <p>first click >> width = 20%</p>
  
  <p>second click >> width = 30%
  .
  .
  .</p>
  
  <p>can do this with DOM?</p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;div&gt;&lt;/div&gt;
  &lt;input id="btn" type="button" value="Progresse Bar +10%"&gt;
  &lt;script src="main.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p><strong>CSS</strong></p>
  
  <pre><code>div {
  width: 10%;
  height: 200px;
  background-color: rgb(173, 230, 18);
  }
  </code></pre>
  
  <p><strong>js</strong></p>
  
  <pre><code>document.getElementById("btn").addEventListener("click", func);
  function func() {
  document.getElementsByTagName("div")[0].style.width+=10;
  }
  </code></pre>