Acrobat Standard 9 vs Acrobat Reader X - Java problem

Hi,
sorry for my english.
I've created a form with AS9 in which a JavaScript send a message to an address specified in a field. Everything works fine if I use AS9 as a reader.
If I open the form with Acrobat X, when I press the button to send the message this error (in the JavaConsole) come out:
RaiseError: Uno dei destinatari specificati non è individuabile.
Doc.mailDoc:21:Field 5_@helpdesk:Mouse Down
===> Uno dei destinatari specificati non è individuabile.
 
The script is this :
 
var cToAddr = getField("0_emailrichiedente").value;var cSubLine = "Richiesta Credenziali: " +
this.getField("0_cognome").value +
" - " +
this.getField("0_nome").value;
var cBody = "Si prega. \n" +
"\n" +
"Cognome Utente: " +
this.getField("0_cognome").value + "\n" +
"Nome Utente: " +
this.getField("0_nome").value
 
this.mailDoc({bUI: true, cTo: cToAddr, cSubject: cSubLine, cMsg: cBody});
 
Any ideas?
Thank you very much in advance