How to delete test steps from zephyr using ZAPI: I have written following code:

[annu2612]

issueID is issueid/teststepIDfunction delete_from_zephyr_teststeps($issueID)
{    $ch = curl_init();        curl_setopt_array($ch, array(                CURLOPT_POST => "DELETE",                CURLOPT_URL => JIRA_URL . '/rest/zapi/latest/teststep/' . $issueID,                CURLOPT_USERPWD => 'USERNAME'. ':' . 'PASSWORD',
                //CURLOPT_PROXY => '10.68.248.34:80',                CURLOPT_HTTPHEADER => array ('Content-Type: application/json'),                CURLOPT_RETURNTRANSFER => true,                CURLOPT_SSL_VERIFYPEER => false,

        ));        $result = curl_exec($ch);        $res_err = curl_error($ch);
        if ($res_err) {                echo "cURL error: $res_err";                                                                      
        } else {              echo "cURL response: $result";
        }        curl_close($ch);
        return json_decode($result);
}

I am getting proper response from zephyr but test steps are not getting deleted.
I have checked, i have admin permission to delete issue as well.