Te expongo mi formulario de "login.php" por si puedes assesorarme:
if (isset($_POST['correo'])) {
$loginUsername=$_POST['correo'];
$password=$_POST['contrasena'];
$MM_fldUserAuthorization = "nivel";
$MM_redirectLoginSuccess = "enviar-foto-paso1_personal-restringido.php";
$MM_redirectLoginFailed = "mal.php";
$MM_redirecttoReferrer = true;
mysql_select_db($database_sitio, $sitio);
$LoginRS__query=sprintf("SELECT correo, contrasena, nivel FROM usuarios WHERE correo=%s AND contrasena=%s",
GetSQLValueString($loginUsername, "text"), GetSQLValueString($password, "text"));
$LoginRS = mysql_query($LoginRS__query, $sitio) or die(mysql_error());
$loginFoundUser = mysql_num_rows($LoginRS);
if ($loginFoundUser) {
$loginStrGroup = mysql_result($LoginRS,0,'nivel');
................ }
header("Location: " . $MM_redirectLoginSuccess );
}
else {
header("Location: ". $MM_redirectLoginFailed );
}
}
?>
............
<form ACTION="<?php echo $loginFormAction; ?>" name="form1" method="POST">
<div align="center">
<table width="67%" border="1">
<tr>
<td width="24%">correo</td>
<td width="76%"><label>
<input name="correo" type="text" id="correo" size="35">
</label></td>
</tr>
<tr>
<td>contraseña</td>
<td><label>
<input name="contrasena" type="password" id="contrasena" size="20">
</label></td>
</tr>
<tr>
<td> </td>
<td><label>
<input type="submit" name="Submit" value="Enviar">
</label></td>
</tr>
</table>
</div>
</form>
<p> </p>
<p align="center"> </p>
</blockquote>
<p align="center"> </p>
</blockquote>
Yo diria por lo que me as respondido que no uso Variables ( globales ) es asi ???