title: External JS not working in my html file?
body: <p>I'm pretty new to JavaScript, I am trying to execute my external JS to html, what im trying to do is to see if the mouseover responds when my mouse hovers one img.</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;meta charset="utf-8"&gt;
      &lt;meta name="viewport" content="width=device-width, initial-scale=1"&gt;
      &lt;title&gt;GWW- A Global Warming Warning...&lt;/title&gt;
  
      &lt;link href="style.css" rel="stylesheet"&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;div class="gridContainer clearfix"&gt;
  &lt;div class="world"&gt;
    &lt;img src="poluicao/poluicao0001.png" alt="Mundo"&gt;
       &lt;div class="botao1"&gt;
         &lt;img src="poluicao/offbuton.png" alt="but1"&gt;
       &lt;/div&gt;
       &lt;div  class="botao2"&gt;
         &lt;!--&lt;a href="#" &gt;//--&gt;
         &lt;img  id="readybotao"  src="degelo/offbutton.gif"  alt="but2"&gt;
        &lt;!-- &lt;/a&gt; //--&gt;
       &lt;/div&gt;
    &lt;/div&gt;
  
    &lt;/div&gt;
      &lt;script src="https://code.jquery.com/jquery-2.1.3.min.js"&gt;&lt;/script&gt;
      &lt;script src="javascript.js"&lt;/script&gt;
  
    &lt;/body&gt;
  
    &lt;/html&gt;
  </code></pre>
  
  <p>And this is my JS file:</p>
  
  <pre><code>function buttonon() {
  alert("If it showed up it worked!");
  }
  
    document.getElementById('readybotao').addEventListener("onmousover",buttonon());
  </code></pre>
  
  <p>What am I doing wrong?</p>