title: HTML + JS: button onclick not working
body: <p>I'm trying to make button (using bootstrap), which calls javascript function. I made this:</p>
  
  <pre><code>&lt;head&gt;
     &lt;script type="text/javascript"&gt;
        function logInClicked() {
        var username = document.getElementById("inputUsername").innerHTML;
        var password = document.getElementById("inputPassword").innerHTML;
        alert(username + ":" + password);
        }
     &lt;/script&gt;
  &lt;/head&gt;
  
  &lt;body&gt;
      &lt;form role="form"&gt;
          &lt;div class="form-group" style="width:300px"&gt;
              &lt;input type="email" class="form-control" id="inputUsername" placeholder="Username"&gt;
          &lt;/div&gt;
          &lt;div class="form-group" style="width:300px"&gt;
              &lt;input type="password" class="form-control" id="inputPassword" placeholder="Password"&gt;
          &lt;/div&gt;
      &lt;/form&gt;
  
      &lt;p&gt;
          &lt;button type="button" style="width:148px" class="btn btn-default btn-lg" id="signUpButton" onclick="signUp();"&gt;Sign Up&lt;/button&gt;
          &lt;button type="button" style="width:148px" class="btn btn-primary btn-lg" id="logInButton" onclick="logInClicked();"&gt;Log In&lt;/button&gt;
      &lt;/p&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>It shows button, but when I click, nothing happens.
  Please help.</p>