how to create option for grid column select in magento - php

Question

I want to create select type for a grid column in magento admin panel.inside _prepareColumns() function
protected function _prepareColumns()
{
if (!$this->getCategory()->getProductsReadonly()) {
$this->addColumn('in_category', array(
'header_css_class' => 'a-center',
'type' => 'checkbox',
'name' => 'in_category',
'values' => $this->_getSelectedProducts(),
'align' => 'center',
'index' => 'entity_id'
));
}
$this->addColumn('entity_id', array(
'header' => Mage::helper('catalog')->__('ID'),
'sortable' => true,
'width' => '60',
'index' => 'entity_id'
));
$this->addColumn('name', array(
'header' => Mage::helper('catalog')->__('Name'),
'index' => 'name'
));
$this->addColumn('position', array(
'header' => Mage::helper('catalog')->__('Position'),
'width' => '1',
'type' => 'select',
'index' => 'position',
'editable' => !$this->getCategory()->getProductsReadonly()
//'renderer' => 'adminhtml/widget_grid_column_renderer_input'
));
return parent::_prepareColumns();
}
Magento uses addColumn() function to create grid column, I want to create a column with select type, but I don't know how to provide it with options

Answer 1

Grid.php
$this->addColumn('state', array(
'header' => Mage::helper('modulename')->__('State'),
'index' => 'state',
'type' => 'options',
'options'=> Mage::getModel('modulename/customerstate')->getStates()
));
Model/Customerstate.php
public function getStates() {
$statesArray = array();
foreach($this->getCollection() as $state){
$statesArray[$state->getId()] = $state->getState();
}
return $statesArray;
}