function getCookie(cookie_name)   
{   
    var allcookies = document.cookie;
    var cookie_pos = allcookies.indexOf(cookie_name);   
    var value="";
    
    if (cookie_pos != -1)   
    {   
        cookie_pos += cookie_name.length + 1;   
        var cookie_end = allcookies.indexOf(";", cookie_pos);   
  
        if (cookie_end == -1)   
        {   
        cookie_end = allcookies.length;   
        }
        value = decodeURI(allcookies.substring(cookie_pos, cookie_end));   
    } 
    return value;   
}