// JavaScript Document
function update_content_type(id,drop_down) {
	url = window.document.getElementById(id).href.split('?')[0];
	query_string = window.document.getElementById(id).href.split('?')[1].split('&');
	
	query_string_variables = [];
	
	for(position = 0;position<query_string.length; position++) {
		query_string_variables.push(query_string[position].split('=')[0]);
	}
	
	content_type_position = find('content_type',query_string_variables);
	
	if(content_type_position == -1)  {
		url = url+'?'+query_string.join('&')+'&content_type='+drop_down[drop_down.selectedIndex].value;
	}
	else {
		query_string.splice(content_type_position,1)
		url = url+'?'+query_string.join('&')+'&content_type='+drop_down[drop_down.selectedIndex].value;
	}
	
	update_link_href(id,url);
}

function switch_content_type(drop_down,uri)	{
	if(drop_down[drop_down.selectedIndex].value == 'content') {		
		window.document.getElementById("toggle_link").style.visibility="hidden";
		window.document.getElementById("toggle_bullet").style.visibility="hidden";
		update_image('header','assets/images/mif_header.gif');
	}
	else	{
		update_image('header','assets/images/mcg_logo_coversheets.gif');
	}
	
	update_content_type('contents_link',drop_down);
	update_content_type('index_link',drop_down);
	
	window.parent.leftFrame.location.href=window.document.getElementById('contents_link').href;
	window.parent.mainFrame.location.href=uri;
}

function update_link_href(id,url) {		
	window.document.getElementById(id).href = url;
}

function update_image(id,new_image) {
	window.document.getElementById(id).src = new_image;
}