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 deleteCookie(name){  
    var exp = new Date();  
    exp.setTime (exp.getTime() - 1); 
    
    var cval = "";
    document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}