atanov,
<body>
<style type="text/css">
div{
border: 1px dashed Gray; padding: 5px; height: 100px; width: 100px
}
</style>
<script> function setClosing()
{
alert(123);
}
var elemdiv = document.createElement('div');
elemdiv.onclick = setClosing;
document.body.appendChild(elemdiv)
</script>
</body>