title: How can I get HTML element value by JavaScript?
body: <pre><code>&lt;div class="gallery_re_form"&gt;
    &lt;form action="http://gall.dcinside.com/?/forms/comment_submit" method="post" accept-charset="utf-8" name="comment_write" id="comment_write" /&gt;
        &lt;div style="display:none"&gt;
            &lt;input type="hidden" name="ci_t" value="625752bb366f010c56e506e5d0f93822" /&gt;
        &lt;/div&gt;
        &lt;input type="hidden" name="ehqo_C" id="ehqo_C" value="spam_key" /&gt;
        &lt;input type="hidden" name="spam_key" id="spam_key" value="rhkdrhgkwlak!!" /&gt;
        &lt;input type="hidden" name="fb8f95190d2b70480acb309f91653d7e4416d4f99a0b67a0b866f06087fdec4588f68fe210675e74919d2ecc50e08f1fd6f75119" id="fb8f95190d2b70480acb309f91653d7e4416d4f99a0b67a0b866f06087fdec4588f68fe210675e74919d2ecc50e08f1fd6f75119" value="b9d3cc45576e30144d8f299fdc61356552989b3aba08238c811b1d3183a104cc2d1d3984af72c4f2eaa2738ca41819d05533731a" /&gt;
        &lt;input type="hidden" name="service_code" value="21ac6e96ad152e8f15a05b7350a24759b5606fa191c17e042e4d0175735f4c61d63153c3ce7b4eb89b565a7f6a04ad0667df75f39625ab6fe0816d23f4bed5387546b52d6874b5c201e54df7b5db9187219b048cffc9ef8a106febabfba125eff122df732d9cc52fcaae8b11c42ff5f6fd5ef81901df4103827e7233615992141c180be76852634d53b60c6f911ccdfc762b3db554d8ee36528547bceede30697120c5291acb255a" /&gt;
        &lt;br /&gt;
        &lt;div class="re_input"&gt;
            &lt;div&gt;
                &lt;ul&gt;
                    &lt;li&gt;
                        &lt;input type="text" name="name" id="name" class="re_name re_in" onfocus="this.style.background='#FFFFFF'" title="nickname" /&gt;
                    &lt;/li&gt;
                    &lt;li&gt;
                        &lt;input type="password" name="password" id="password" class="re_pw re_in" onfocus="this.style.background='#FFFFFF'" title="password" /&gt;
                    &lt;/li&gt;
                &lt;/ul&gt;
            &lt;/div&gt;
        &lt;/div&gt;
    &lt;/form&gt;
  </code></pre>
  
  <p>I'm trying to rewrite google chrome extensions. I want to get <code>#spam_key</code> s <code>#service_code</code>s value in this HTML response.</p>
  
  <p>I have not used JavaScript.</p>
  
  <p>How can I get HTML element id (spam_key, service_code) and value by JavaScript?</p>