title: HTML onclick="myFunction" not working
body: <p>First, i have checked several tutorial sites to clarify syntax such as the OnClick event and the prompt property and relocated the javascript from body to head (I heard this can fix browser-related problems).</p>
  
  <p>For some reason OnClick event does nothing. I have tested website in-browser and radio buttons load correctly.</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
  &lt;script&gt;
      function checkSkillLevel() {
          if(document.getElementById('skill_Easy').checked) {
              var ok = prompt("You chose Easy");
          }
          else if(document.getElementById('skill_Medium').checked) {
              var ok = prompt("You chose Medium");
          }
          else if document(getElementById('skill_Hard').checked) {
              var ok = prompt("You chose Hard");
          }
          else {
              var ok = prompt("Welcome to my tic tac toe game! To get started, please pick a skill level.");
          }
      }
  &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;table cellpadding="10"&gt;
      &lt;tr&gt;
              &lt;td&gt;&lt;h1&gt;Tic Tac Toe&lt;/h1&gt;&lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;td&gt;
              &lt;form action="" onclick="checkSkillLevel()"&gt;
              &lt;input type="radio" name="skill" value="Easy" id="skill_Easy" onclick="checkSkillLevel();"&gt;Easy&lt;br&gt;
              &lt;input type="radio" name="skill" value="Medium" id="skill_Medium"&gt;Medium&lt;br&gt;
              &lt;input type="radio" name="skill" value="Hard" id="skill_Hard"&gt;Hard&lt;br&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
  </code></pre>
  
  <p>
  </p>
  
  <p>Also, I would prefer pure Javascript (no JQuery please) for any ideas.</p>