/**
 * Read the JavaScript cookies tutorial at:
 *   http://www.netspade.com/articles/javascript/cookies.xml
 */

/**
 * Sets a Cookie with the given name and value.
 *
 * name       Name of the cookie
 * value      Value of the cookie
 * [expires]  Expiration date of the cookie (default: end of current session)
 * [path]     Path where the cookie is valid (default: path of calling document)
 * [domain]   Domain where the cookie is valid
 *              (default: domain of calling document)
 * [secure]   Boolean value indicating if the cookie transmission requires a
 *              secure transmission
 */
function setCookie(name, value, expires, path, domain, secure)
{
    document.cookie= name + "=" + escape(value) +
        ((expires) ? "; expires=" + expires.toGMTString() : "") +
        ((path) ? "; path=" + path : "") +
        ((domain) ? "; domain=" + domain : "") +
        ((secure) ? "; secure" : "");
}

/**
 * Gets the value of the specified cookie.
 *
 * name  Name of the desired cookie.
 *
 * Returns a 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));
}

/**
 * Deletes the specified cookie.
 *
 * 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)
 */
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";
    }
}


/*  Expands/Collapses the submenus 
	id = Id of the submenu group
	num = number of submenus to toggle  */
function toggle_submenu(id,num) {
	var c,elem,expand_id,imgelem;
	expand_id = getCookie("expand_id");  // get cookie value
		
	imgelem = id + "img";	//define image element
	img = document.getElementById(imgelem); 	//define the image
	if (!expand_id == id) {
		img.src = './images/plus.gif';
	} else {
		img.src = './images/minus.gif';
	}
	
	// Expand or close request menu
	for (c = 1; c <=num; c++) {	//  loop through each submenu
		elem = id + "-" + c;		//  set the id of the submenu
		doc = document.getElementById(elem);		//define the element
		var toggle = doc.style.display ? '' : 'none';	//compare the element, it will toggle between '' or none.
		doc.style.display = toggle;			//set the new value
	}
	if (toggle == '') {
		img.src = './images/minus.gif';
		setCookie("expand_id",id);	//set cookie with ID of open menu
		setCookie("expand_num",num);  //set cookie with num of submenus for the above ID
	} else {
		img.src = './images/plus.gif';
		setCookie("expand_id",'');	//set cookie with ID of open menu
		setCookie("expand_num",'');  //set cookie with num of submenus for the above ID
	}
}