Cluster y otros:
 Me van a tener que disculpar pero esto no me da resultados. He probado ahora con una nueva variante de código y me sigue dando errores: 
 Código PHP:
    <?
          if(!isset($phase)){
           echo "<form action='uploadadmin.php?action=admin&type=".$HTTP_COOKIE_VARS['usertype']."&ses=".$HTTP_COOKIE_VARS['sessionid']."&phase=second' method='post' name='filesadmin' id='filesadmin'>
                 <table width='300' border='1' align='center' cellpadding='0' cellspacing='0' bordercolor='#98AAB1'>
                 <tr bgcolor='#BFCFE0'>
                 <td colspan='2' class='menutop'>Cantidad de ficheros a subir </td>
                 </tr>
                 <tr class='txtrg'>
                 <td width='325'>Cantidad de Ficheros a subir: </td>
                 <td width='169' class='txt'><input name='cantidad' type='text' id='cantidad' size='5' maxlength='5'></td>
                 </tr>
                 <tr>
                 <td colspan='2'><div align='center'>
                 <input name='next' type='submit' class='txtcn' id='next' value='Siguiente >>'>
                 </div></td>
                 </tr>
                 </table>
                 </form>";
          }elseif((isset($phase))&&($phase=="second")){
           echo "<form action='upload.php?action=admin&type=".$HTTP_COOKIE_VARS['usertype']."&ses=".$HTTP_COOKIE_VARS['sessionid']."&phase=upload' enctype='multipart/form-data' method='post' name='filesadmin' id='filesadmin'>
                 <table width='300' border='1' align='center' cellpadding='0' cellspacing='0' bordercolor='#98AAB1'>
                 <tr bgcolor='#BFCFE0'>
                 <td colspan='2' class='menutop'>Cantidad de ficheros a subir </td>
                 </tr>";
                 for($i=0;$i<$_POST['cantidad'];$i++){
                  echo "
                  <tr class='txtrg'>
                  <td width='325'>Fichero No. ".$i.": </td>
                  <td width='169' class='txt'>
                  <input name='file[$i]' type='file' id='file[$i]'>
                  <input name='cant' type='hidden' id='cant' value='".$_POST['cantidad']."'>
                  </td>
                  </tr>";
                 }
           echo "<tr>
                 <td colspan='2'><div align='center'>
                 <input name='next' type='submit' class='txtcn' id='next' value='Siguiente >>'>
                 </div></td>
                 </tr>
                 </table>
                 </form>";
          }
          ?>    
  y el fichero upload.php es este: 
 Código PHP:
   
 <?php
 $newdir = mkdir("files",0777);
 $tmpdir = "marxismo/".$newdir;
 if((isset($_GET['action']))&&($_GET['action']=="admin")){
  if((isset($_GET['phase']))&&($_GET['phase']=="upload")){
   for($i=0;$i<$_POST['cant'];$i++){
     $dir = $tmpdir."/".$_FILES['file']['name'][$i];
     $bool = move_uploaded_file($_FILES['file']['tmp_name'][$i], $dir);
     if($bool)
      echo "OK";
     else
      echo "Pepe";
   }
  }
 }
?>    
  me da este error: 
 Cita:  
Warning: move_uploaded_file(marxismo/1/1082320851.jpg): failed to open stream: No such file or directory in c:\program files\apache group\apache\htdocs\marxismo\upload.php on line 8
 
Warning: move_uploaded_file(): Unable to move 'C:\WINDOWS\TEMP\phpF4.tmp' to 'marxismo/1/1082320851.jpg' in c:\program files\apache group\apache\htdocs\marxismo\upload.php on line 8
Pepe
Warning: move_uploaded_file(marxismo/1/connected_multiple_big.jpg): failed to open stream: No such file or directory in c:\program files\apache group\apache\htdocs\marxismo\upload.php on line 8
 
Warning: move_uploaded_file(): Unable to move 'C:\WINDOWS\TEMP\phpF5.tmp' to 'marxismo/1/connected_multiple_big.jpg' in c:\program files\apache group\apache\htdocs\marxismo\upload.php on line 8
Pepe
    Salu2  
