If you'd like to redirect to another domain without the user having to do anything you can use a link with the property:
target="_parent"
as said previously, and then use:
document.getElementById('link').click();
to have it automatically redirect.
Example:
<!DOCTYPE HTML>
<html>
<head>
</head>
<body>
<a id="link" target="_parent" href="outsideDomain.html"></a>
<script type="text/javascript">
document.getElementById('link').click();
</script>
</body>
</html>
Note: The javascript click() command must come after you declare the link.