grazie ma continua a partire il form:
codice:
<script language="javascript" type = "text/javascript">

function vai(){
 	
	document.forms['form'].target = '_blank';
return true;

    </script>

<form method="POST" enctype="multipart/form-data" action="index.asp" name="rapporti" onsubmit="return submitIt( this ) && vai( );">