title: dropdown field names in cakephp
body: <p>For cakephp 1.3, I've created a drop down for birthday like so</p>
  
  <pre><code> echo $form-&gt;input('User.birthday', 
              array(
  
                  'label' =&gt; __("form_birthday", "true") , 
                  'class' =&gt; 'date',
                  'selected' =&gt; 'empty',
                  'dateFormat' =&gt; 'DMY',
                  'minYear' =&gt; date('Y') - 90,
                  'maxYear' =&gt; date('Y') - 18,
                  'separator'=&gt; " ",
                  'empty' =&gt; __("form_select", true),
  
              )
          );  
  </code></pre>
  
  <p>which produces</p>
  
  <pre><code> &lt;div class="input date"&gt;&lt;label for="UserBirthdayMonth"&gt;Month &amp;amp; Year of      Birth&lt;/label&gt;&lt;select id="UserBirthdayDay" class="date" name="birthday"&gt;
   &lt;option value=""&gt;- Select  -&lt;/option&gt;
   .....
   &lt;/select&gt; &lt;select id="UserBirthdayMonth" class="date" name="birthday"&gt;
     &lt;option value=""&gt;- Select  -&lt;/option&gt;
     &lt;option value="01"&gt;January&lt;/option&gt;
     &lt;option value="02"&gt;February&lt;/option&gt;
     &lt;option value="03"&gt;March&lt;/option&gt;
     &lt;option value="04"&gt;April&lt;/option&gt;
     &lt;option value="05"&gt;May&lt;/option&gt;
     &lt;option value="06"&gt;June&lt;/option&gt;
     &lt;option value="07"&gt;July&lt;/option&gt;
     &lt;option value="08"&gt;August&lt;/option&gt;
     &lt;option value="09"&gt;September&lt;/option&gt;
     &lt;option value="10"&gt;October&lt;/option&gt;
     &lt;option value="11"&gt;November&lt;/option&gt;
     &lt;option value="12"&gt;December&lt;/option&gt;
     &lt;/select&gt; &lt;select id="UserBirthdayYear" class="date" name="birthday"&gt;
     &lt;option value=""&gt;- Select  -&lt;/option&gt;
     .....
     &lt;/select&gt;&lt;/div&gt;
  </code></pre>
  
  <p>Notice how the name attribute of the dropdowns are all "birthday". How can I change this in cake so that the name attributes of the three dropdowns above are not all the same? I'd like them be something like "birthday_month", "birthday_year" and "birthday_day".</p>