самое простое.
HTML
Код
<div class="open" onclick="$('.okno' <img rel="usm" src="/smiles/wink.gif" border="0" align="absmiddle" alt=";)" /> .show();"></div>
<div class="okno">
<div class="closed" onclick="$('.okno' <img rel="usm" src="/smiles/wink.gif" border="0" align="absmiddle" alt=";)" /> .hide();"></div>
</div>
CSS
Код
.open, .closed {width: 30px; height: 30px; border-radius: 50%; display: block;}
.open {background: green;}
.closed {background: red;}
.okno {display: none; width: 300px; height: 150px; background: #fff; box-shadow: 0 0 2px 0 #000; border-radius: 3px;}
demo