interazione tra funzione e loop

[horace]

Qui imposto la funzione

<%function prepara_data(gg,mm,aaaa)
    vardataunica= (gg & "/" & mm & "/" & aaaa)
    vardatadal= (gg & "/" & mm & "/" & aaaa)
    vardataal= (gg & "/" & mm & "/" & aaaa)
    end function 

E subito dopo la devo utilizzare in un ciclo do while

do while not (Tab.EOF)
%>
  <tr>
    <td></td>

    <td>
    <% 
     if isnull (Tab("dataunica")) then
                if isnull (Tab("datadal")) then
                    response.write(Tab("altradata"))
                else
                    
call prepara_data(datePart("d",(Tab("datadal"))), datePart("m",(Tab("datadal"))), datePart("yyyy",(Tab("datadal"))))
                    response.write("Dal " & (vardatadal))
                    
call prepara_data(datePart("d",(Tab("dataal"))), datePart("m",(Tab("dataal"))), datePart("yyyy",(Tab("dataal"))))
                    response.Write (" al " & (vardataal))
                end if
            else

                                       call prepara_data(datePart("d",(Tab("dataunica"))),  datePart("m",(Tab("dataunica"))), datePart("yyyy",(Tab("dataunica"))))
                        Response.write (vardataunica)
            end if %>
</td>
<%Tab. movenext
loop
%>