но кликать в рамку надо всё равно
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<style type="text/css">
div.a, div.b{
height:100px;
border: 1px solid gray;
text-align: center;
}
div.b{display:none;}
div.b.Expanding{display: block}
</style>
<script type="text/javascript">
var b_h = 100
function show_b(){
var b = document.getElementById("divb")
if(b.className.search("Expanding") < 0){
b.style.height = 0
b.className += " Expanding"
}else{
var h = parseInt(b.style.height)
if(h >= b_h) return
b.style.height = h + 10 + "px"
}
setTimeout(show_b, 100)
}
</script>
</head>
<body>
<div class="a" onclick="show_b()"></div>
<div class="b" id ="divb"></div>
<p>just next paragraph</p>
</body>
</html>
Думаю, дело в размерах