PHP question

I am creating a form in expression web 4. Everything appears to be working correctly when I click submit on the form. All of the fields are filled out and the php script I have does send it to an email address. My question is the following; when I fill out all of the fields in the form, not all of the fields show up. It appears I can only get past 2 fields being filled out before it starts sending blank forms. see the code below.

$msg =$_POST['WSD-Name'];
$msg2=$_POST['WSD-Phone'];
$msg3=$_POST['WSD-Email'];
$msg4=$_POST['WSD-Address'];
$msg5=$_POST['WSD-City'];
$msg6=$_POST['WSD-ZIP'];
$msg7=$_POST['WSD-DOB'];
$msg8=$_POST['WSD-Fitness-Level'];
$to='[email protected];
$subject='Wsd application';

mail($to,$subject,$msg8,$msg7,$msg6,$msg5,$msg4,$msg3,$msg2,$msg);

 

Could you show us the form's html please ...