ok so I post this info to the url

Code:
    [ClientSessionID] => q1lcu0gmqfdiq72h9csnj96vn1
    [CustomerID] => 187
    [CustomerName] => AndySutton
    [UserName] => changed
    [Amount] => 8.08
    [ReturnURL] => http://mywebsiteurl/store/index.php?main_page=checkout_process
    [BackButtonCaption] => false
    [PromptCancel] => true
    [PageTitle] => Order confirmation Page
    [CustomerFirstName] => Andy
    [CustomerLastName] => Sutton
    [CustomerStreet2] => 919 western ave chicago
    [CustomerStreet3] =>  
    [CustomerEmail] => Andy
    [CustomerDayPhone] => 4257897858
    [CustomerNightPhone] => 4257897858
    [CustomerMobile] => Sutton
    [CustomerFax] => 
    [CustomerProvince] => 
    [CustomerCountryID] => 
    [Date] => January 16, 2009, 12:28 am
    [IP] => 216.43.193.242
    [Session] => q1lcu0gmqfdiq72h9csnj96vn1
    [url] => https://hps.webportal.test.secureexchange.net";
Now I use

$this->authorize = curl_exec($ch);
$this->commError = curl_error($ch);
$this->commErrNo = curl_errno($ch);

$this->commInfo = @curl_getinfo($ch);
curl_close ($ch);

as in the file and when I try to print the $response

$stringToParse = $this->authorize;
echo "Here goes the response";
echo $stringToParse;
exit();

All I get is empty string
Can someone pls tel me whats going on wrong here?
Thanks