title: html link onclick pop up a form
body: <p>i'd like to pop up a form when click a link.</p>
  
  <pre><code>&lt;a title='%s' onclick='return popupform()'  href='#'&gt; ABC &lt;/a&gt;
  </code></pre>
  
  <p>the form is like:</p>
  
  <pre><code>&lt;form id="contactus" action="javascript:submit_form()" method="post" accept-charset="UTF-8"&gt;
  &lt;input type="hidden" name="submitted" id="submitted" value="1"&gt;
      &lt;label for="chinese"&gt;Chinese: &lt;/label&gt;&lt;br&gt;
      &lt;input type="text" name="cs" id="cs" value="" maxlength="50"&gt;&lt;br&gt;
  &lt;label for="english"&gt;English:&lt;/label&gt;&lt;br&gt;
      &lt;input type="text" name="en" id="en" value="" maxlength="50"&gt;&lt;br&gt;
      &lt;input type="submit" name="Save" value="Save"&gt;
      &lt;input type="submit" name="Delete" value="Delete"&gt;
      &lt;input type="submit" name="Add" value="Add"&gt;
      &lt;input type="submit" name="Close" value="Close"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>how to achieve  it?</p>