title: How to set layout when call module in component joomla 2.5
body: <p>In a component how to call a module:</p>
  
  <pre><code>tmpl
  ---default.php
  ---hello.php
  mod_hello.php
  mod_hello.xml
  helper.php    
  
  $module = JModuleHelper::getModule('mod_hello');
  echo JModuleHelper::renderModule ($module );
  </code></pre>
  
  <p>When I <code>echo</code> the result using layout <code>default</code>, how to show layout of module mod_hello is <code>hello</code> layout</p>