Api code in PHP issue

I write below code using php,to add the records in tickets through api but i got error message like "4832Error while adding records. check xml values"

Please any help me

$subj=$_POST['subject6'];

$desc=$_POST['description'];

$email=$_POST['email10'];

$contactnm=$_POST['contactname'];

$ch= curl_init(' https://support.zoho.com/api/xml/requests/addrecords');

curl_setopt($ch, CURLOPT_VERBOSE, 1);

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);

curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLOPT_POST, 1);

$authtoken = "myauthno";

$portal="nhmweb";

$department="nhmweb";

$xmldata = '<?xml version="1.0" encoding="UTF-8"?>

<fl val="Contact Name">'.$contactnm.'</fl>

<fl val="Email">'.$email.'</fl>

</row>

</requests>';

$query = array('authtoken'=>$authtoken,'portal'=>$portal,'department'=>$department,'xml'=>$xmldata);

$query = http_build_query($query);

curl_setopt($ch, CURLOPT_POSTFIELDS, $query);

echo $response = curl_exec($ch);

curl_close($ch);

Thanks
Satya NHM