no guarda che ho messo $_SERVER

questo è il form:

codice:
<link rel="stylesheet" type="txt/css" href="css1.css"> 
<link rel="stylesheet" type="text/css" href="css_menu.css" > 
<script src="fixedbackground3.js" type="text/javascript"></script> 
</head> 
<body onLoad="fixedBackground('blackboard.jpg');"> 
<p align="center"> [img]titolo2.png[/img] </p>
 <div align="center" > <div class="intestazione" style="margin-top:0px;"> 
<div style="position:absolute;margin-left:600px;" > 
<form id="frmLogin" action="<? $_SERVER['PHP_SELF']?>" align="right" method="POST" > <fieldset style="width:150px;" > <legend>
<font color="white" face="eraser">login:</font></legend> 
<input type="text" name="Username" size="20" value="Inserisci l'utente" class="tiepido" onfocus="FocusUser();" onblur="BlurUser();"> 
 
<input type="password" name="Password" size="20" value="Password" class="tiepido" onfocus="FocusPass();" onblur="BlurPass()";> 
 
<input type="button" value="Login" onClick="controlla();"> <font color="white"><u>registrati</u></font> </fieldset> </form> </div>