Código HTML:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Documento sin título</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript" type="text/JavaScript">
function contar(obj) {
if(obj.checked){
document.getElementById("div1").style.display='block';
document.getElementById("uid_4234").checked=true;
}else{
document.getElementById("div1").style.display='none';
document.getElementById("uid_4234").checked=false;
}
}
</script>
</head>
<body>
<td><input type="checkbox" name="chk1" id="chk1" onclick="contar(this)" />
<div id="div1" style="display: none"><input type="checkbox" name="uid_4234" id="uid_4234" />Hola soy la div</div>
</body>
</html> Ahí va...
Quim