<?php
 
header("Content-type: application/vnd.mozilla.xul+xml" );
 
echo "<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>";
echo "<?xml-stylesheet href=\"chrome://global/skin/\" type=\"text/css\"?>";
?>
<window
    id="auth"
    title="Recherche de fichiers"
    xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
    orient="vertical">
     
<script src="./js/auth.js" type="application/x-javascript"></script>
 
<commandset>
 <command id="doLogin" oncommand="doLogin()"/>
</commandset>  
 
 
<spacer flex="1" />
<hbox>
<spacer flex="1" />
<groupbox>
 <caption label="Connexion" />
 <label control="login" value="Identifiant :" />
 <textbox id="login" type="text" />
 <label control="password" value="Mot de passe :" />
 <textbox id="password" type="password" />
 <button label="Se connecter" command="doLogin" />
 <!--<progressmeter id="identifier" mode="determined" />-->
</groupbox>
<spacer flex="1" />
</hbox>
<spacer flex="4" />
</window>

function doLogin(login, password) {
 
 
 var login = document.getElementById("login" ).value;
 var password = document.getElementById("password" ).value;
 
 if(login == "" ) {
  alert("L'identifiant est obligatoire !" );
  return false;
 }
 if(password == "" ) {
  alert("Le mot de passe est obligatoire !" );
  return false;
 }
 else {
  ...
 }
}

<?php
require_once("./conf/config.inc.php" );
require_once("./lib/functions.inc.php" );
 
$sql = new mysql(DB_SERVER, DB_USER, DB_PASSWORD, DB_NAME);
 
 
function doLogin($sql, $login, $password) {
 $sql->sql("SELECT user_login, user_passwd  
       FROM ".DB_PREFIX."user
       WHERE user_login='".$login."'
       AND user_passwd=md5('".$password."')" );
       
    if($sql->num_rows()==1) {
     return true;
    }
    else {
     return false;
    }
}
?>