Magento Capture 方法不起作用

I have payment Method code like this

    <?php 
class Company_Cashondelivery_Model_Createorder extends Mage_Payment_Model_Method_Abstract
{   
    protected $_code = 'cashondelivery';
    protected $_canCapture = true;
    protected $_canUseCheckout = true;
    public function capture(Varien_Object $payment, $amount)
    {
                $paymentInfo = $this->getInfoInstance();  
                Mage::Log('Got Info Instance'); //This is shown in Log file.
                Mage::Log($amount); //This is shown in Log file
                Mage::Log($payment);                 
                    $xml='<?xml version="1.0" encoding="utf-8" ?>'.
                        '<transaction>'.
                        '<customerDetails>'.
                        '<address>This is, address, Purple Talk, 600100</address>'. //I dont know how to get Address as string here
                        '<contactNo>'.$paymentInfo->getOrder()->getBillingAddress()->getTelephone().'</contactNo>'.
                        '<email>'.$paymentInfo->getOrder()->getBillingAddress()->email().'</email>'.
                        '<firstName>'.$paymentInfo->getOrder()->getBillingAddress()->getFirstName().'</firstName>'.
                        '<lastName>'.$paymentInfo->getOrder()->getBillingAddress()->getLastName().'</lastName>'.
                        '</customerDetails>'.
                        '<orderDetails>'.
                        '<pincode>'.$paymentInfo->getOrder()->getBillingAddress()->getPostCode().'</pincode>'.
                        '<clientOrderID>'.$paymentInfo->getOrder()->getIncrementId().'</clientOrderID>'.
                        '<deliveryDate>20-7-20111</deliveryDate>'.
                        '<orderAmount>'.$amount.'</orderAmount>'.
                        '<productDetails>';
                    Mage::Log($xml);//This is not there in log file    
                    foreach ($paymentInfo->getOrder()->getAllItems() as $item) 
                        {
                            $xml.='<productDetails>'.
                            '<productID>'.$item->getProductId().'</productID>'.
                            '<productQuantity>'.$item->getQtyOrdered().'</productQuantity>'.
                            '<unitCost>'.$item->getPrice().'</unitCost>'.
                            '</productDetails>';
                        }
                       $xml.='</orderDetails>'.
                        '<additionalInformation>'.
                        '<parameters>'.
                        '<name>Some Name</name>'.
                        '<value>Some Value</value>'.
                        '</parameters>'.
                        '<parameters>'.
                        '<name>Some Name2</name>'.
                        '<value>Some value2</value>'.
                        '</parameters>'.
                        '</additionalInformation>'.
                        '</transaction>';
                        Mage::Log($xml);
                        $url = "http://services.abc.com/rest/service/createOrder";
                        Mage::Log('Loading url : '.$url); //This is not there in Log;
                        $ch = curl_init($url) ;
                        curl_setopt($ch, CURLOPT_HEADER,true);
                        curl_setopt($ch, CURLOPT_POST, true);
                        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1 );
                        curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
                        curl_setopt($ch, CURLOPT_HTTPHEADER, array('username:xxxxx','password:xxxxxx','Content-Type:application/xml'));
                        $response = curl_exec($ch);
                        Mage::Log($response); //This is not there in Log file;
                   return $this;    
    }     
}
?>

Config.xml 文件是这样的

<?xml version="1.0"?>
<config>
    <modules>
       <Company_Cashondelivery>
<!-- declare module's version information for database updates -->
          <version>0.1.0</version>
       </Company_Cashondelivery>
    </modules>
    <global>
<!-- declare model group for new module -->
        <models>
<!-- model group alias to be used in Mage::getModel('newmodule/...') -->
            <cashondelivery>
<!-- base class name for the model group -->
                <class>Company_Cashondelivery_Model</class>
            </cashondelivery>    
        </models>
        <helpers>
            <cashondelivery>
                <class>Company_Cashondelivery_Helper</class>
            </cashondelivery>
        </helpers> 
<!-- declare resource setup for new module -->
        <resources>
<!-- resource identifier -->
            <cashondelivery_setup>
<!-- specify that this resource is a setup resource and used for upgrades -->
                <setup>
<!-- which module to look for install/upgrade files in -->
                    <module>Company_Cashondelivery</module>
                </setup>
<!-- specify database connection for this resource -->
                <connection>
<!-- do not create new connection, use predefined core setup connection -->
                    <use>core_setup</use>
                </connection>
            </cashondelivery_setup>
            <cashondelivery_write>
                <connection>
                  <use>core_write</use>
                </connection>
            </cashondelivery_write>
            <cashondelivery_read>
               <connection>
                <use>core_read</use>
              </connection>
            </cashondelivery_read>
        </resources>
    </global>

<!-- declare default configuration values for this module -->
    <default>
        <payment>
            <cashondelivery>
                <active>1</active>
                <model>cashondelivery/createorder</model>
                <order_status>pending</order_status>
                <payment_action>authorize_capture</payment_action>
                <title>Company</title>                
            </cashondelivery>
         </payment>
    </default>
</config>

<?xml version="1.0"?>
<config>
   <sections>
        <payment>
            <groups>
                <cashondelivery translate="label" module="cashondelivery">
                    <label>Company Cash On delivery</label>
                    <sort_order>670</sort_order>
                    <show_in_default>1</show_in_default>
                    <show_in_website>1</show_in_website>
                    <show_in_store>0</show_in_store>
                    <fields>
                        <active translate="label">
                            <label>Enabled</label>
                            <frontend_type>select</frontend_type>
                            <source_model>adminhtml/system_config_source_yesno</source_model>
                            <sort_order>1</sort_order>
                            <show_in_default>1</show_in_default>
                            <show_in_website>1</show_in_website>
                            <show_in_store>0</show_in_store>
                        </active>
                        <order_status translate="label">
                            <label>New order status</label>
                            <frontend_type>select</frontend_type>
                            <source_model>adminhtml/system_config_source_order_status_processing</source_model>
                            <sort_order>4</sort_order>
                            <show_in_default>1</show_in_default>
                            <show_in_website>1</show_in_website>
                            <show_in_store>0</show_in_store>
                        </order_status>
                        <title translate="label">
                            <label>Title</label>
                            <frontend_type>text</frontend_type>
                            <sort_order>2</sort_order>
                            <show_in_default>1</show_in_default>
                            <show_in_website>1</show_in_website>
                            <show_in_store>0</show_in_store>
                        </title>
                    </fields>
                </cashondelivery>
            </groups>
        </payment>
    </sections>
</config>

<?xml version="1.0"?>
<config>
    <modules>
        <Company_Cashondelivery>
            <active>true</active>
            <codePool>local</codePool>
         </Company_Cashondelivery>
    </modules>
    <depends> 
        <Mage_Payment /> 
    </depends> 
</config>