cURL login simulator gets no cookie response

I am new to cURL functions and while i understand what it should be doing, i am having a hard time making it work. I have a script building the variables and then calling a function to create a curl_init(); variable.

here is my try, what am i doing wrong (sorry for being vague) :

$loginUrl = 'http://ift.tt/15GaPy2'; 
$loginFields = array(
    'URI'=>'https://www.link.htm',
    'AUTHMETHOD'=>'UserPassword',
    'Time'=>(strtotime(date('Y-m-d H:i:s')) * 1000)-10000),
    'LOC'=>'en_US',
    'usr_name'=>'clear_text_usrname%40domainname', 
    'usr_password'=>'clear_text_password',
    'usr_check'=>'' //usr_check is the checkbox 
                    //"remember my username" input on the page.
                    //Should i send it as well?
);
$login = $cURLclass->getUrl($loginUrl, $loginFields);

Where URI, AUTHMETHOD, Time and LOC are hardcoded hidden input fields that i have to match the same input (Time is the unix epoch time in miliseconds). the "%40" in the usr_name is used to recreate a "@", because cURL uses @ to declare filenames as far as i read on the subject.

Then, my getUrl function :

function getUrl($url, $vars='') {

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $vars);
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); // BYPASS SSL VALIDATION; CANT GET FILE ON SERVER TO WORK WTV
    curl_setopt($ch, CURLOPT_COOKIEJAR, 'cookies/cookies.txt');
    curl_setopt($ch, CURLOPT_COOKIEFILE, 'cookies/cookies.txt');
    $buffer = curl_exec($ch);
     //echo curl_error($ch);
    curl_close($ch);
    return $buffer;
}

All in all the whole page, after authentification, should be dropped in the $login variable as far as i understand, and then should be ready for the next operation. This function already worked as far as i know but adding new variables (because the form on the page im trying to access as more inputs) simply doesn't allow it to work.

Thanks.

P.S. : It's all PHP

EDIT : Thank you Patrick LC for the clean editing i really appreciate the help.