Go through app settings

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class ConfigReader : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        AppSettingsReader asr = new AppSettingsReader();
        string[] keys = ConfigurationManager.AppSettings.AllKeys;

        foreach (string key in keys) 
        {
            lblKeys.Text = lblKeys.Text.ToString() + "<p>" + key + " - " + (string)asr.GetValue(key, key.GetType()) + "</p>";
        }
        
    }
}