           end
        end</PRE>

  <P>
    We cannot allow our file system to be spammed with such heretic messages
    behind our backs, so it is a good choice to evaluate the component inside
    the sandbox:
  </P>
  <PRE class=code>
    open unpack Safe.eval(Url.fromString "local", component) : (val run : unit -> string)
    val s = run()</PRE>

  <P>
    Evaluating the call to <TT>run</TT> will fail due to its attempt to
    invoke <TT>TextIO.openOut</TT>, which causes
    a <TT>Security</TT> exceptio