title: Portlet - multiple buttons in form
body: <p>I'm trying to write a simple calculator portlet and I have problem with passing value of one of the buttons to my portlet. There's part of my .jsp:</p>
  
  <pre><code>&lt;portlet:actionURL var = "digit" name = "onDigitPressed"&gt;
  &lt;portlet:param name="jspPage" value = "/html/calc/view.jsp"/&gt;
  &lt;/portlet:actionURL&gt;
  
  &lt;aui:form action="&lt;%= digit %&gt;" method="post" &gt;
  
  &lt;table&gt;
  &lt;tr&gt;&lt;td&gt;
  &lt;aui:button name="button" type = "submit" value="7" id="7"/&gt;  
  &lt;/td&gt;&lt;td&gt;
  &lt;aui:button name="button" type = "submit" value="8" id="8" /&gt; &lt;/td&gt;&lt;td&gt;
  &lt;aui:button name="button" type = "submit" value="9" id="9"/&gt; &lt;/td&gt;&lt;td&gt;
  &lt;/tr&gt;&lt;tr&gt;&lt;td&gt;
  .
  .//more buttons
  .
  &lt;/tr&gt;&lt;tr&gt;&lt;td&gt;
  &lt;aui:button name="button" type = "submit" value="0" id="0" /&gt;  &lt;/td&gt;&lt;td&gt;
  &lt;aui:button name="button" type = "submit" value="." id="." /&gt;  &lt;/td&gt;&lt;td&gt;
  &lt;/td&gt;
  &lt;/tr&gt;
  &lt;/table&gt;
  &lt;/aui:form&gt;
  </code></pre>
  
  <p>and in <code>onDigitPressed</code> method:</p>
  
  <pre><code>request.getParameter("button");//returns always null
  </code></pre>
  
  <p>I want to pass value of the button somehow and I want to have only one actionURL to deal with all these buttons. And it would be good to have only one form too. There must be some way, but I have no idea how to do this, I'm new in portlets and JSP.</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>My explanation of problem isn't very clear - I want to pass value of <strong>clicked</strong> button. I need that information to know what user wants to compute. Sure I can just spam with <code>actionURL</code>s and <code>form</code>s, but I want to do this with one form and actionURL.  I bet it has something to do with <code>onClick</code> attribute and I'm pretty sure I can't use javascript, because it has to be done on server side and javascript is executed on client side.</p>