title: Submit button in a PHP form is unclickable
body: <p>The problem is the submit button, it's just unclickable, and nothing really happens (=screen doesn't change) when I am trying to submit an email to myself by using the form.</p>
  
  <p>This is my code:</p>
  
  <pre><code>&lt;div class="col-sm-6"&gt;
  &lt;h4 class="font-alt"&gt;Get in touch&lt;/h4&gt;
  &lt;br&gt;
  &lt;form id="contact-form" role="form" novalidate=""&gt;
  &lt;div class="form-group"&gt;
  &lt;label class="sr-only" for="cname"&gt;Name&lt;/label&gt;
  &lt;input type="text" id="cname" class="form-control" name="cname"       placeholder="Name*" required="" data-validation-required-message="Please enter your name."&gt;
  &lt;p class="help-block text-danger"&gt;&lt;/p&gt;
  &lt;/div&gt;
  
  &lt;div class="form-group"&gt;
  &lt;label class="sr-only" for="cemail"&gt;Your Email&lt;/label&gt;
  &lt;input type="email" id="cemail" name="cemail" class="form-control" placeholder="Your E-mail*" required="" data-validation-required-message="Please enter your email address."&gt;
  &lt;p class="help-block text-danger"&gt;&lt;/p&gt;
  &lt;/div&gt;
  
  &lt;div class="form-group"&gt;
  &lt;textarea class="form-control" id="cmessage" name="cmessage" rows="7" placeholder="Message*" required="" data-validation-required-message="Please enter your message."&gt;&lt;/textarea&gt;
  &lt;p class="help-block text-danger"&gt;&lt;/p&gt;
  &lt;/div&gt;
  
  &lt;div class="text-center"&gt;
  &lt;button type="submit" class="btn btn-block btn-round btn-d"&gt;Submit&lt;/button&gt;
  &lt;/div&gt;
  
  &lt;/form&gt;
  &lt;div id="contact-response" class="ajax-response font-alt"&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And this is the PHP I'm working with:</p>
  
  <pre><code>&lt;?php
  // Mail settings
  $to = "info@liannesiemensma.com";
  $subject = "Contact form";
  if (isset($_POST["name"]) &amp;&amp; isset($_POST["email"]) &amp;&amp; isset($_POST["message"])) {
  
  $content  = "Name: "     . $_POST["name"]    . "\r\n";
  $content .= "Email: "    . $_POST["email"]   . "\r\n";
  $content .= "Message: "  . "\r\n" . $_POST["message"];
  
  if (mail($to, $subject, $content, $_POST["email"])) {
  
  $result = array(
  "message" =&gt; "Thanks for contacting me! I will do my best to reply in a timely manner.",
  "sendstatus" =&gt; 1
  );
  
  echo json_encode($result);
  } else {
  
  $result = array(
  "message" =&gt; "Sorry, something is wrong.",
  "sendstatus" =&gt; 0
  );
  
  echo json_encode($result);
  }
  }
  ?&gt;
  </code></pre>
  
  <p>What am I doing wrong?</p>