ciao,
ho provato a seguire il tuo suggerimento ma ho rilevato questo errore:

Warning: oci_connect() [function.oci-connect]: OCIEnvNlsCreate() failed. There is something wrong with your system - please check that PATH includes the directory with Oracle Instant Client libraries in C:\workspace_php\prova\index.php on line 13

Warning: oci_error() [function.oci-error]: OCIError: unable to find error handle in C:\workspace_php\prova\index.php on line 15

Fatal error: in C:\workspace_php\prova\index.php on line 16