ecco un esempio completamente funzionante:
codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>esempio</title>
<script language="JavaScript" type="text/javascript">
<!--
function copia() {
var nomefile=document.nomeform.nomecampofile.value.substr(document.nomeform.nomecampofile.value.lastIndexOf('\\')+1);
document.nomeform.nomecampo.value=nomefile;
}
//-->
</script>
</head>
<body>
<form name="nomeform">
<input type="file" name="nomecampofile">
<input type="text" name="nomecampo"> <input type="button" onclick="copia();" value="Copia" />
</form>
</body>
</html>
ciao