// name - name of the cookie
// value - value of the cookie
// [expires] - expiration date of the cookie (defaults to end of current session)
// [path] - path for which the cookie is valid (defaults to path of calling document)
// [domain] - domain for which the cookie is valid (defaults to domain of calling document)
// [secure] - Boolean value indicating if the cookie transmission requires a secure transmission
// * an argument defaults when it is assigned null as a placeholder
// * a null placeholder is not required for trailing omitted arguments
function setCookie(name, value, expires, path, domain, secure) 
{
	var curCookie = name + "=" + escape(value) 
  		+ ((expires) ? "; expires=" + expires.toGMTString() : "") 
  		+ "; path=" + ((path) ? path : "/") 
  		+ ((domain) ? "; domain=" + domain : "") 
  		+ ((secure) ? "; secure" : "");
    document.cookie = curCookie;
}



// name - name of the desired cookie
// * return string containing value of specified cookie or null if cookie does not exist
function getCookie (name) 
{
	var dc = document.cookie;
	var prefix = name + "=";
	var begin = dc.indexOf("; " + prefix);
	
	if (begin == -1)
	{
		begin = dc.indexOf(prefix);
		if (begin != 0) 
		{
			return null;
		}
	}
	else
	{
		begin += 2;
	}
	
	var end = document.cookie.indexOf (";", begin);
	if (end == -1)
	{
		end = dc.length;
	}
	
	return unescape (dc.substring (begin + prefix.length, end));
}



// name - name of the cookie
// [path] - path of the cookie (must be same as path used to create cookie)
// [domain] - domain of the cookie (must be same as domain used to create cookie)
// * path and domain default if assigned null or omitted if no explicit argument proceeds
function deleteCookie(name, path, domain)
{
	if (getCookie (name))
	{
		document.cookie = name + "=" 
			+ "; path=" + ((path) ? path : "/")
			+ ((domain) ? "; domain=" + domain : "")
			+ "; expires=Thu, 01-Jan-70 00:00:01 GMT";
	}
}