Magento Add Country and State Dropdown in Magento admin Form

Hi Magento friends today's i'm share how to Add Country and State Dropdown in Magento admin Form in magento 

When you have no states for pirticular country the it show a textbox in textbox you can add state name for country.

Open your form which is in Yournamespace/Modulename/Block/Adminhtml/Modulename/Edit/Tab/Form.php then add below fields

$country = $fieldset->addField('country', 'select', array(

    'name' => 'country',

    'label' => 'Country',

    'values' => Mage::getModel('adminhtml/system_config_source_country')->toOptionArray(),

    'onchange' => 'getstate(this)',

    'class' => 'required-entry',

    'required' => true,

        ));

if (Mage::registry('modulename_data')->getData('state')) {

    $fieldset->addField('state', 'text', array(

        'name' => 'state',

        'label' => 'State',

        'class' => 'required-entry',

        'required' => false,

    ));

} else {

    $statevalues = '';

    if (Mage::registry('modulename_data')->getData('store_image')) {

        $regionModel = Mage::getModel('directory/region')->load(Mage::registry('modulename_data')->getData('store_image'));

        $region = $regionModel->getName();

        $statevalues = array(Mage::registry('modulename_data')->getData('store_image') => $region);

    }

    $fieldset->addField('state', 'select', array(

        'name' => 'state',

        'label' => 'State',

        'value' => Mage::registry('modulename_data')->getData('region_id'),

        'values' => $statevalues,

        'required' => false,

    ));

}

$country->setAfterElementHtml("<script type=\"text/javascript\">

            function getstate(selectElement){

                var reloadurl = '" . $this

                ->getUrl('modulename/adminhtml_modulename/state') . "country/' + selectElement.value;

                new Ajax.Request(reloadurl, {

                    method: 'get',

                    onLoading: function (stateform) {

                        $('state').update('Searching...');

                    },

                    onComplete: function(stateform) {

                        $('state').replace(stateform.responseText);

                    }

                });

            }

    </script>");

Now Create State Action in modulenamecontroller.php file which will be like this

public function stateAction() {

    $countrycode = $this->getRequest()->getParam('country');

    if ($countrycode != '') {

        $statearray = Mage::getModel('directory/region')->getResourceCollection()->addCountryFilter($countrycode)->load();

        $state = "<select class='select' name='state' id='state' class='required-entry validate-select'><option value=''>Please Select</option>";

        foreach ($statearray as $_state) {

            $state .= "<option value='" . $_state->getDefaultName() . "'>" . $_state->getDefaultName() . "</option>";

            $yes = 1;

        }

        $state .= "</select>";

    }

}