function showPageTypes(filter, isCaseStudy) 
{  
	var page = (isCaseStudy ? "/Audience-Insight/case-studies.aspx" : "/Advertising/TV/sponsorship-opportunities.aspx");
	window.location.href = page  + "?fo="+filter[filter.selectedIndex].value;
} 

function showPageTypesCurrentPage(filter) 
{  
	var currQS = location.href; 
	var val = filter[filter.selectedIndex].value;
	var re = new RegExp("([?|&])fo=.*?(&|$)","i");
	if (currQS.match(re)) location.href = currQS.replace(re,'$1' + "fo=" + val + '$2');
	else location.href = currQS + (location.search.length>0?"&":"?") + "fo=" + val;
}