ecco il form:


<form method="post" name="form1" action="gestione_privata.asp?selezione=utenti" onsubmit="return confirm('Sei sicuro di voler eliminare gli utenti selezionati?');">
<table width="100%" class="SfondoTabelleDinamiche">
<tr>
<td>
<table width="100%" border="1">
<tr>
<td class="IntestazioneCampiTabella"></td>
<td class="IntestazioneCampiTabella">Nome</td>
<td class="IntestazioneCampiTabella">Cognome</td>
<td class="IntestazioneCampiTabella">Indirizzo</td>
<td class="IntestazioneCampiTabella">Telefono</td>
<td class="IntestazioneCampiTabella">Cellulare</td>
<td class="IntestazioneCampiTabella">E-mail</td>
<td class="IntestazioneCampiTabella">Username</td>
</tr>
<%
do while not tbrs.eof
%>
<tr class="TestoCampiDinamici">
<td>
<input name="cancella" type="checkbox" value = "<%=tbrs("uten_id").value%>">
</td>
<% if tbrs("uten_nome").value <> "" then %>
<td><% response.Write(tbrs("uten_nome").value) %></td>
<%else %>
<td> </td>
<% end if%>
<% if tbrs("uten_cognom").value <> "" then %>
<td><% response.Write(tbrs("uten_cognom").value) %></td>
<%else %>
<td> </td>
<% end if%>
<% if tbrs("uten_indiri").value <> "" then %>
<td><% response.Write(tbrs("uten_indiri").value) %></td>
<%else %>
<td> </td>
<% end if%>
<% if tbrs("uten_telfis").value <> "" then %>
<td><% response.Write(tbrs("uten_telfis").value) %></td>
<%else %>
<td> </td>
<% end if%>
<% if tbrs("uten_cellul").value <> "" then %>
<td><% response.Write(tbrs("uten_cellul").value) %></td>
<%else %>
<td> </td>
<% end if%>
<% if tbrs("uten_email").value <> "" then %>
<td><% response.Write(tbrs("uten_email").value) %></td>
<%else %>
<td> </td>
<% end if%>
<% if tbrs("uten_userna").value <> "" then %>
<td><% response.Write(tbrs("uten_userna").value) %></td>
<%else %>
<td> </td>
<% end if%>
</tr>
<%
tbrs.movenext
loop
%>
</table>
</td>
</tr>
<tr>
<td>

<div align="right">
<input type="button" name="indietro" value="Indietro" onClick="javascript:history.back()">
<input type="submit" name="delete_utenti" value="Elimina">
<input type="button" name="chiudi" value="Chiudi" onClick="vbscript:self.close">
</div>
</p>
</td>
</tr>
</table>
</form>


se metto il ; finale alla confirm non compare proprio il messaggio!!!