<div id="div1" style="visibility:visible;">hello</div>
<input type=button name=b1 onclick="vbscript:click1()" value="change_visibility">
<script language=vbscript>
function click1()
if not div1.style.visibility="hidden" then
div1.style.visibility="hidden"
else
div1.style.visibility="visible"
end if
end function
</script>