Get posted variables with http request

Hi

I have 3 files. I am trying to post variables with post so I can process them with http request. I couldn't manage to get posted variables. Here is my files.

presentation.php
-------------------
$html .= "<form action=addRemoveMembers.php method=post id=theHttpForm name=theHttpForm>";
$html .= "<input type=hidden id=id name=id value=$value>";
$html .= "<td width=60><input type=\"button\" value=\"   >>   \" name=\"B1\" onClick=\"javascript:document.getElementById('switch').value=0; addRemoveMembers('$resource','../$resource/getSearchResults.php?module=$resource&id=$value&start=0&side=0','$foreign_field','$value','0');
getContent('../$resource/getSearchResults.php?module=$resource&id=$value&start=0&side=0','member');\">

functions.js
-------------
function addRemoveMembers(module, url, foreign_field_value, value, side) {
      xmlhttp=setHTTPObject();
      var url = "../"+module+"/addRemoveMembers.php";
      xmlhttp.open("POST", url, false);
      xmlhttp.send(null);
}

addRemoveMembers.php
-----------------------------
$db->createSequence("linfo_group_group_sequence");
$new_id=$db->nextId("linfo_group_group_sequence");
$query = "INSERT INTO linfo_group_group (id, group_id, group_member_id)      VALUES($new_id, $_POST[id], 22);";
$result = $db->query($query);