title: submit can't send data of textarea
body: <p>Recently I study html and javascript.
  I know that in html form sends data to server
  between  and .</p>
  
  <p>However, in my case it doesn't.</p>
  
  <p>here is my code</p>
  
  <pre><code>function wReply() {
               if(document.getElementById("repInputContent").value == "")  {
                  alert("type anything for reply");
                  document.getElementById("repInputContent").focus();
                  return;
               }
               document.reply.submit();
          }
  </code></pre>
  
  <p>this is javascript function that work with input type button.</p>
  
  <p>And this is html form code</p>
  
  <pre><code>&lt;tr id="replyInput"&gt;
                      &lt;td colspan="3"&gt;
                      &lt;form action="/wReply" accept-charset="utf-8" name="reply" method="post"&gt;
                          &lt;input type="hidden" name="num" value="&lt;%=num%&gt;"&gt;
                          &lt;input type="hidden" name="writer" value="&lt;%=writer%&gt;"&gt;
                          &lt;input type="hidden" name="page" value="&lt;%=page%&gt;"&gt;
                          &lt;textarea rows="4" cols="40" id="repInputContent"&gt;&lt;/textarea&gt;
                      &lt;/form&gt;
                      &lt;/td&gt;
                      &lt;td&gt;&lt;input type="button" value="submit" onclick="wReply()"&gt;&lt;/td&gt;
              &lt;/tr&gt;
  </code></pre>
  
  <p>I code a table and want to send hidden type datas and textarea data.
  I think it works but actually server can receive hidden type datas.</p>
  
  <p>What is the problem?</p>