<?php
$serveur='localhost';
$user='root';
$password='xxxx';
$base='db';
$champs=array(
"member"=>array("id","group","login","lastname","firstname","email","pswd","account","searchingfor","searchingfordistance","searchedfor","searchedfordistance","mydescription","groupdescription","searchdescription","resourcesdescription"),
    "place"=>array("id","idm","ids","name","town","postalcode","address","coord")
);

$connexion = mysql_connect("$serveur","$user","$password") or die ("Impossible de se connecter à la base de données");
mysql_select_db("$base",$connexion) or die("Erreur de connexion a la base de donnees");

$fieldtypes = mysql_query("SHOW FIELDS FROM place");

ob_start();
var_export($fieldtypes);
$tab_debug=ob_get_contents();
ob_end_clean();
$fichier=fopen('gs.log','w');
fwrite($fichier,$tab_debug);
fclose($fichier);

... (rest of code works)

$fields = array();
$fieldtypes = mysql_query("SHOW FIELDS FROM place");
if ($fieldtypes) {
  while ($row = mysql_fetch_assoc($fieldtypes)) {
    $fields[] = $row;
  }
}
ob_start();
// Dump your $fields array
var_export($fields);
$tab_debug=ob_get_contents();
ob_end_clean();

// Don't quote these vars -- it's poor practice
$connexion = mysql_connect("$serveur","$user","$password")