Pagination not working in custom admin module

Question

I made a custom module in admin section for seller management. I updated the details using a CSV file. There are about 200 entries. Now, when I try to go to the next page, it redirects to the same page.

The search bar on top of each column in the grid is also not working. When I try to search an entry using the search bar, it redirects me to the same page again.

This is the code of my block.

class COC_Managesellers_Block_Adminhtml_Managesellers extends Mage_Adminhtml_Block_Widget_Grid_Container
{
     public function __construct()
     {
         $this->_controller = 'adminhtml_managesellers';
         $this->_blockGroup = 'managesellers';
         $this->_headerText = Mage::helper('managesellers')->__('Seller Manager');
         parent::__construct();
     }
 }

Grid.php

public function __construct()
{
    parent::__construct();
    $this->setId('sellerGrid');
    $this->setDefaultSort('managesellers_id');
    $this->setDefaultDir('ASC');
    $this->setSaveParametersInSession(true);
    $this->setUseAjax(true);
    $this->setVarNameFilter('product_filter');

}

protected function _getStore()
{
    $storeId = (int) $this->getRequest()->getParam('store', 0);
    return Mage::app()->getStore($storeId);
}

protected function _prepareCollection()
{
    $store = $this->_getStore();
    $collection = Mage::getModel('managesellers/managesellers')->getCollection();
    $this->setCollection($collection);
    parent::_prepareCollection();
    return $this;
}

protected function _addColumnFilterToCollection($column)
{
    if ($this->getCollection()) {
        if ($column->getId() == 'websites') {
            $this->getCollection()->joinField('websites',
                'managesellers/product_website',
                'website_id',
                'seller_id=managesellers_id',
                null,
                'left');
        }
    }
    return parent::_addColumnFilterToCollection($column);
}

protected function _prepareColumns()
{
    $this->addColumn('managesellers_id',
        array(
            'header'=> Mage::helper('managesellers')->__('ID'),
            'width' => '50px',
            'index' => 'managesellers_id',
    ));
    $this->addColumn('name',
        array(
            'header'=> Mage::helper('managesellers')->__('Name'),
            'index' => 'name',
    ));
    $this->addColumn('address',
        array(
            'header'=> Mage::helper('managesellers')->__('Address'),
            'index' => 'address',
    ));
    $this->addColumn('shipping_charges',
        array(
            'header'=> Mage::helper('managesellers')->__('Shipping Charges'),
            'index' => 'shipping_charges',
    ));
    $this->addColumn('min_value',
        array(
            'header'=> Mage::helper('managesellers')->__('Minimum Order Value'),
            'index' => 'min_value',
    ));


    $this->addColumn('action',
        array(
            'header'    => Mage::helper('managesellers')->__('Action'),
            'width'     => '50px',
            'type'      => 'action',
            'getter'     => 'getId',
            'actions'   => array(
                array(
                    'caption' => Mage::helper('managesellers')->__('Edit'),
                    'url'     => array(
                        'base'=>'*/*/edit',
                        'params'=>array('managesellers_id'=>$this->getRequest()->getParam('managesellers_id'))
                    ),
                    'field'   => 'managesellers_id'
                )
            ),
            'filter'    => false,
            'sortable'  => false,
            'index'     => 'managesellers_id',
    ));

    return parent::_prepareColumns();
}

protected function _prepareMassaction()
{
    $this->setMassactionIdField('managesellers_id');
    $this->getMassactionBlock()->setFormFieldName('managesellers_id');

    $this->getMassactionBlock()->addItem('delete', array(
         'label'=> Mage::helper('managesellers')->__('Delete'),
         'url'  => $this->getUrl('*/*/massDelete'),
         'confirm' => Mage::helper('managesellers')->__('Are you sure?')
    ));

    Mage::dispatchEvent('adminhtml_managesellers_grid_prepare_massaction', array('block' => $this));
    return $this;
}

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

public function getRowUrl($row)
{
    return $this->getUrl('*/*/edit', array(
        'store'=>$this->getRequest()->getParam('store'),
        'managesellers_id'=>$row->getId())
    );
}

How can I make them work ?

Please help.

Answer 1

Please Put gridAction in controller:

public function gridAction()
{
    $this->loadLayout();
    $this->getResponse()->setBody(
        $this->getLayout()->createBlock('coc/adminhtml_managesellers_grid')->toHtml()
    );
}