/**********************************************************************
*   CG_menu.js
*   Written by Gareth Richards
*   September 2007
***********************************************************************/

var lastId = "none";
var cookieName = "cg_menu_active_item";

function setCookie(c_name,value,expiredays)
{
    var exdate=new Date()
    exdate.setDate(exdate.getDate()+expiredays)
    document.cookie=c_name+ "=" +escape(value)+((expiredays==null) ? "" : ";expires="+exdate.toGMTString())
} 
function getCookie(c_name)
{
    if (document.cookie.length>0)
    {
        c_start=document.cookie.indexOf(c_name + "=")
        if (c_start!=-1)
        { 
            c_start=c_start + c_name.length+1 
            c_end=document.cookie.indexOf(";",c_start)
            if (c_end==-1)
                c_end=document.cookie.length
            return unescape(document.cookie.substring(c_start,c_end))
        } 
    }
return ""
}
function shrinkItem(menuId)
{
    document.getElementById(menuId).style.display="none";
    setCookie(cookieName,'none',5);
}
function expandItem(menuId)
{
    document.getElementById(menuId).style.display="block";
    setCookie(cookieName,menuId,5);
}
function initMenu()
{
    menuId = getCookie(cookieName);
    if(menuId != "")
        toggleDisplay(menuId);
}
function toggleDisplay(menuId)
{
    if( menuId != "none" )
    {
        if(menuId == lastId)
        {    changeDisplay(menuId);
             lastId = "none";
        }
        else
        {
            if(lastId != "none")
                changeDisplay(lastId);
            changeDisplay(menuId);
            lastId = menuId;
        }
    }
}
function changeDisplay(menuId)
{
    if( menuId != "" && menuId != "none")
    {
        if( document.getElementById(menuId).style.display == "block")
        {
            shrinkItem(menuId);
        }
        else
            expandItem(menuId);
    }
}
function clearCookie()
{
    setCookie(cookieName, "", -1);
}