salve ho questo script che funziona benissimo, per caricare un file alla volta.
ora vi spiego meglio, io vorrei inserire un ulteriore csalla input con il pulsante sfoglia.
questo è lo script
prova.asp
Codice PHP:
<script language="javascript" type="text/javascript">
<!--
function startUpload(){
      document.getElementById('f1_upload_process').style.visibility = 'visible';
      document.getElementById('f1_upload_form').style.visibility = 'hidden';
      return true;
}

function stopUpload(success){
      var result = '';
      if (success == 1){
         result = '<span class="msg">File inviato con successo!<\/span>

';
      }
      else {
         result = '<span class="emsg">Errore durante il caricamento del file!<\/span>

';
      }
      document.getElementById('f1_upload_process').style.visibility = 'hidden';
      document.getElementById('f1_upload_form').innerHTML = result + '<label>File: <input name="myfile" type="file" size="30" /><\/label><label><input type="submit" name="submitBtn" class="sbtn" value="Upload" /><\/label>';
      document.getElementById('f1_upload_form').style.visibility = 'visible';      
      return true;   
}
//-->
</script>   
</head>

<body>
       <div id="container">
            <div id="content">
                <form action="upload.php" method="post" enctype="multipart/form-data" target="upload_target" onsubmit="startUpload();" >
                     <p id="f1_upload_process">Caricamento
[img]loader.gif[/img]
</p>
                     <p id="f1_upload_form" align="center">

                         <label>File:  
                              <input name="myfile" type="file" size="30" />
                         </label>
                         <label>
                             <input type="submit" name="submitBtn" class="sbtn" value="Invia" />
                         </label>
                     </p>
                     
                     <iframe id="upload_target" name="upload_target" src="#" style="width:0;height:0;border:0px solid #fff;"></iframe>
                 </form> 
upload.php
Codice PHP:
<?php






   // Edit upload location here
   $destination_path = getcwd().DIRECTORY_SEPARATOR;

   $result = 0;
   
   $target_path = $destination_path . basename( $_FILES['myfile']['name']);

   if(@move_uploaded_file($_FILES['myfile']['tmp_name'], $target_path)) {
      $result = 1;
   }
   
   sleep(1);
?>

<script language="javascript" type="text/javascript">window.top.window.stopUpload(<?php echo $result; ?>);</script>
grazie a tutti