problemi con controllo form mail

[Sleazy]

<script Language="javascript">

function controllo()
{
if ((document.form.e-mail.value=="") || (document.form.e-mail.length < 7 ) || (document.form.e-mail.value.indexOf("@") == -1 ))
{
alert ('Inserire un indirizzo email valido');
document.form.e-mail.focus();
return false ;
}
}
</script>

e la prima riga del form e':

<form name="form" OnSubmit="return controllo()" method="post" action="contatto.asp" >