// JavaScript Document

function ChangeLang(lang)
{
	var url = String(window.location).split("/").pop();
	var url_parts = url.split("?");
	
	if(url_parts.length==1)
	{
		window.location = url+'?lang='+lang;
	}
	else
	{
		var regexp = /lang/;	
		var new_url = url_parts[0];
		var old_elements = url_parts[1].split("&");
		var separator = null;
		var exists = false;
		
		for(var i=0; i<old_elements.length; i++)
		{
			if(!separator) separator = '?';
			else separator = '&';
			
			if(regexp.test(old_elements[i]))
			{
				new_url+=separator+"lang="+lang;
				exists = true;
			}
			else
			{
				new_url+=separator+old_elements[i];
			}
			
		}
		
		if(!exists) new_url+="&lang="+lang;
		window.location = new_url;
	}
}