Q1023 How can I retrieve the toolbars of the current window which were removed by the previous example?

<SCRIPT LANGUAGE="JavaScript"><!--
function on() {
    window.open('','_top','menubar=1,location=1,toolbar=1,personalbar=1,status=1,scrollbars=1');
}
//--></SCRIPT>

<FORM>
<INPUT TYPE=SUBMIT VALUE="On" onClick="on()">
</FORM>
</HTML>