Variable name in POST request

Hello,

I have capture a emission packet, and this is a HTTP/XML protocol using POST request. I saw the source code, but normaly, when we send a post request, we have to send a variable with its value to an url/server right ? So, how can I know the variable name or the multiple variable name use for contact the serveur with a POST request ?

POST /newsoap/soap/mim.php HTTP/1.1
Host: site.com
User-Agent: SITE/0.15 CFNetwork/548.0.3 Darwin/11.0.0
Content-Length: 1139
Accept: */*
Content-Type: text/xml; charset=utf-8
Accept-Language: fr-fr
Accept-Encoding: gzip, deflate
Cookie: PHPSESSID=20mgf6gtg00svvdg91mlh4t5e0
Connection: keep-alive
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<requet xmlns="http://site.com/">
<lang>fr</lang><pass>toto</pass>
<xml><![CDATA[<?xml version="1.0"?>
<Membrep nbInvitations="" nbMessages="" nbNews="" enabled="" nbCommunaute="" nbEvenement="" nbActivite="" nbLieux="" type_activite_id="" creneau_val="" activite_id="" creneau_id="" fonction="" secteur="" ville="" genre="" daten="" Added="" PK="" activiteImage="" activiteNiveau="" activiteNom="" statu="" image="" visible="" facebookId="" twitterId="" linkedId="" telephone="" email="" prenom="" nom=""><listeElements/><Positionp nom="" PK="" type="" longitude="" latitude=""/></Membrep>
]]></xml>
<nomrequet>inscription</nomrequet>
<param1><![CDATA[fr]]></param1>
<param2><![CDATA[AAAAAA]]></param2>
<param3><![CDATA[BBBBBBB]]></param3>
<param4><![CDATA[CCCCCC]]></param4>
<param5><![CDATA[DDDDDD]]></param5>
<param6><![CDATA[EEEEEEEE]]></param6>
</requet>
</soap:Body>
</soap:Envelope>