Magento 1.9 – Fixing Fatal Error: Call to a Member Function setSaveParametersInSession() on a Non-Object

I am getting the error in my custom admin module –

 Fatal error: Call to a member function setSaveParametersInSession() on a non-object in /var/www/html/B2BMarkets/app/code/core/Mage/Adminhtml/Block/Widget/Grid/Container.php on line 66

Siteadmin_Approval is my module name.
Here is controller –

class Siteadmin_Approval_Adminhtml_ApprovalController extends Mage_Adminhtml_Controller_action
{

    protected function _initAction() {
        $this->loadLayout()
            ->_setActiveMenu('siteadmin/approval');

        return $this;
        }


    public function indexAction() { 

        $this->_initAction()
            ->renderLayout();
    }

        public function viewAction() {

                $this->_initAction();
                $this->_addContent($this->getLayout()
                            ->createBlock('approval/adminhtml_approval_view'))
                    ->_addLeft($this->getLayout()
                            ->createBlock('approval/adminhtml_approval_view_tabs'));
                $this->renderLayout();
        }
}

and Block –

app/code/local/Siteadmin/Approval/Block/Adminhtml/Approval/View.php


class Siteadmin_Approval_Block_Adminhtml_Approval_View extends
                    Mage_Adminhtml_Block_Widget_Grid_Container {
  public function __construct()
  {
        parent::__construct();
        $this->_controller = 'adminhtml_approval_view';
        $this->_blockGroup = 'approval';
        $this->_headerText = Mage::helper('approval')->__('Company Users');


        $this->_removeButton('add');
        $data = array(
        'label' =>  'Back',
        'onclick'   => 'setLocation(\'' . $this->getUrl('*/*') . '\')',
        'class'     =>  'back'
            );
        $this->addButton ('my_back', $data, 0, 100,  'header'); 

        $this->_removeButton('back');
  }

}

and app/code/local/Siteadmin/Approval/Block/Adminhtml/Approval/View/View.php

class Siteadmin_Approval_Block_Adminhtml_Approval_View extends
                    Mage_Adminhtml_Block_Widget_Grid {
  public function __construct()
  {
        parent::__construct();
        $this->setId('company_user_id');
        $this->setUseAjax(FALSE);

        $this->setDefaultSort('id');
        $this->setDefaultDir(Varien_Data_Collection::SORT_ORDER_ASC);
        $this->setSaveParametersInSession(TRUE);
  }

  protected function _prepareCollection()
  {
     $comp_id = Mage::getSingleton('admin/session')->getCompanyId();

     $catalog_id = $this->getRequest()->getParam("id");

     try {
      $collection = Mage::getModel('newuser/companyuser')->getCollection()
                     ->addFieldToFilter("company_details_id", array("eq"=>$this->getRequest()->getParam("id")));


      $this->setCollection($collection);

     } catch(Exception $e)
      {
            Mage::getSingleton('adminhtml/session')
                                 ->addError($e->getMessage());
               Mage::getSingleton('adminhtml/session')
                ->settestData($this->getRequest()
                                   ->getPost()
               );
               $this->_redirect('*/*/index',
                           array('id' => $this->getRequest()
                                               ->getParam('id')));
               return;
      }

      return parent::_prepareCollection();
  }

  protected function _prepareColumns()
  {
      $this->addColumn('first_name', array(
          'header'    => Mage::helper('approval')->__('First Name'),
          'align'     =>'right',
          'width'     => '50px',
          'index'     => 'first_name',
           'align'     => 'left',
      ));


     $this->addColumn('is_active', array(
          'header'    => Mage::helper('approval')->__('Is Active'),
          'align'     =>'center',
          'index'     => 'is_active',
          'type'      => 'text',
          'width'     => '150px',
          'align'     => 'left',
          'filter'    => FALSE

      ));


      return parent::_prepareColumns();
  }



  public function getGridUrl()    {
      return $this->getUrl('*/*/view/', array('_current'=>true));    

  }
}

can anybody please help me to figure out what I am doing wrong here?

Thanks,