Unable to add form in content section magento admin custom extension

Question

I am working on magento admin. Try to adding grid with add edit action. But I am stuck at strange issue my form is display in left sidebar under selected tab. Don't know why this happen. Please help me if you know why this is happen

Code of XXXX/XXX/Block/Adminhtml/Dragon/Edit/Form.php

<?php

class XXXX_XXX_Block_Adminhtml_Dragon_Edit_Form extends Mage_Adminhtml_Block_Widget_Form
{
  protected function _prepareForm()
  {
      $form = new Varien_Data_Form(array(
                                      'form_id' => 'edit_form',
                                      'action' => $this->getUrl('*/*/save', array('form_id' => $this->getRequest()->getParam('form_id'))),
                                      'method' => 'post',
                                      'enctype' => 'multipart/form-data'
                                   )
      );

      $form->setUseContainer(true);
      $this->setForm($form);
      $this->setTemplate('XXXX/form.phtml');
      return parent::_prepareForm();
  }
}

Answer 1

In your extension you should have this file:

[Namespace]/[Module]/Block/Adminhtml/[Entity]/Edit/Form.php or something similar. This is the form container class.

Inside that file you should have a method _prepareForm that should look like this:

protected function _prepareForm()
{
    $form = new Varien_Data_Form(array('id' => 'edit_form', 'action' => $this->getData('action'), 'method' => 'post'));
    $form->setUseContainer(true);
    $this->setForm($form);
    return parent::_prepareForm();
}

Make sure that the id you pass to the Varien_Data_Form constructor is edit_form.
Use the cms page module as an example: (Mage_Adminhtml_Block_Cms_Page_Edit_Form).