If you use parent.close() to close the frameset you might get the error message:
This is a bug exploit
The following script will suppress this error message and close the frameset
In the frame closing the frameset.
<script type="text/javascript">
<!--
function close_all(){
parent.opener = top
parent.close()
}
// -- >
</script>
Use an event to call close_all()
<script type="text/javascript">
<!--
function close_frameset(){
opener.parent.opener = top
opener.parent.close()
}
window.onerror=sh
function sh(){
return true
}
onload=close_frameset
// -- >
</script>
See Example Frameset