title: Magento - Adding a new field for shipping address during onepage checkout process
body: <p>I want to add a new field "custom_house_no" for the shipping address during the onepage checkout process.</p>
  
  <p>I have added the below code in my custom extension mysql file "mysql4-install-0.1.0.php" 
      <pre><code>
      // Customer Address
      $entityTypeId     = $installer->getEntityTypeId('customer_address');
      $attributeSetId   = $installer->getDefaultAttributeSetId($entityTypeId);
      $attributeGroupId = $installer->getDefaultAttributeGroupId($entityTypeId, $attributeSetId);</p>
  
  <pre><code>$installer-&gt;addAttribute('customer_address', 'custom_house_no',  array(
      'label'             =&gt; 'Custom House No',
      'input'             =&gt; 'text', // Input field type textbox
      'type'              =&gt; 'varchar', // Store varchar data type 
      'frontend'          =&gt; '', //frontend model
      'backend'           =&gt; '', //backend model
      'visible'           =&gt; 1, //true
      'required'          =&gt; 0, //false
      'user_defined'      =&gt; 1, 
      'default'           =&gt; '', //default value
      'searchable'        =&gt; 0,
      'filterable'        =&gt; 0, 
      'comparable'        =&gt; 0,
      'visible_on_front'  =&gt; 0,
      'unique'            =&gt; 0,
      'global'      =&gt; Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL 
      //  'class'             =&gt; '',
      //  'source'            =&gt; 'catalog/category_attribute_source_page',
  ));
  
  $installer-&gt;addAttributeToGroup(
      $entityTypeId,
      $attributeSetId,
      $attributeGroupId,
      'custom_house_no',
      '150'       //last Magento's attribute position in General tab is 140
  );
  
  $attribute = Mage::getSingleton('eav/config')-&gt;getAttribute('customer_address', 'custom_house_no');
  $attribute-&gt;setData('used_in_forms', array('customer_register_address', 'customer_address_edit', 'adminhtml_customer_address')); // Setting the relation between the attribute and forms in which this attribute will be used
  $attribute-&gt;save();`
  </code></pre>
  
  <p></code></pre></p>
  
  <p>I have also made a class in folder MY/CustomExtension/Model/Entity/Setup.php 
      <pre><code>
      class MY_CustomExtension_Model_Entity_Setup extends Mage_Eav_Model_Entity_Setup {
      }
      </code></pre></p>
  
  <p>I have also added the class name in the extension config file.
      <pre><code>
      Link to config code : <a href="http://pastebin.com/Li7CqEyj" rel="nofollow">Config File Content</a>
      </code></pre></p>
  
  <p>And in the shipping template file i have added the textbox with the name "custom_house_no".</p>
  
  <p>The attribute has been added successfully and he relationship with the forms, but all the data is getting save in the database except the "custom_house_no" field.</p>
  
  <p>I don't know what is wrong with my code.</p>