XMLSerializer problem

Mit spørgsmål lyder således:

jeg vil gerne serialisere følgende output:
<?xml version="1.0"?>
<customStates xmlns="http://schemas.microsoft.com/09/2005/communicator/customStates" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schemas.microsoft.com/09/2005/communicator/customStates/livecommteam/sites/main/ice/Wave%2012%20Docs/CustomActivities.xsd">
      <customState ID="1" availability="online">
              <activity LCID="1033">Working from Home</activity>
              <activity LCID="1036">Equivalent French String for - Working from Home</activity>
              <activity LCID="1030">Dansk streng</activity>
      </customState>
      <customState ID="2" availability="busy">
              <activity LCID="1033">In a Live Meeting</activity>
              <activity LCID="1036">Equivalent French String for - In a Live Meeting </activity>
              <activity LCID="1030">Dansk streng</activity>
      </customState>
      <customState ID="3" availability="busy">
              <activity LCID="1033">Working</activity>
              <activity LCID="1030">Working</activity>
              <activity LCID="1036">Equivalent French String for - Working</activity>
      </customState>
      <customState ID="4" availability="do-not-disturb">
              <activity LCID="1033">Relaxing with my family</activity>
              <activity LCID="1036">Relaxing with my family</activity>
              <activity LCID="1030">Relaxing with my family</activity>
      </customState>
</customStates>


Jeg har lavet nedstående klasse, men ved ikke hvorledes jeg kan sætte xsi:schemalocation eller hvorledes jeg skal kunne oprette flere "activity" per element i viste xml.

Håber at i kan hjælpe :)
using System;
using System.Collections.Generic;
using System.Text;
using System.Xml.Serialization;
using System.Xml;
using System.IO;

namespace UC.DemoSetup
{
    /// <summary>
    /// Contains information regarding CustomPresence
    /// </summary>
    [XmlRootAttribute("CustomStates", Namespace = "http://schemas.microsoft.com/09/2005/communicator/customStates", IsNullable = false)]
    public class CustomStates 
    {
        private CustomState customState;
        public CustomState CustomState
        {
            get { return this.customState; }
            set { this.customState = value; }
        }
       
        public CustomStates() { }

        public CustomStates(CustomState customState)
        {
            this.customState = customState;
        }
    }
    public class CustomState
    {
        private int customStateId;
        private string Avalability;
        private Activity activity;

        [XmlAttribute("ID")]
        public int CustomStateID
        {
            get{return this.customStateId;}
            set{this.customStateId = value;}
        }
       
        [XmlAttribute("availability")]
        public string Availability
        {
            get{return this.Avalability;}
            set{this.Avalability = value;}
        }

        public Activity Activity
        {
            get { return this.activity; }
            set { this.activity = value; }
        }

        public CustomState() { }

        public CustomState(int customStateId, string availability, Activity activity)
        {
            this.customStateId = customStateId;
            this.Avalability = availability;
            this.activity = activity;
        }
    }

    public class Activity
    {
        private int lcid;
        private string presenceName;

        [XmlAttribute("LCID")]
        public int LCID
        {
            get { return this.lcid; }
            set { this.lcid = value; }
        }

        [XmlText()]
        public string PresenceName
        {
            get { return this.presenceName; }
            set { this.presenceName = value; }
        }

        public Activity(){}

        public Activity(int lcid, string presenceText)
        {
            this.lcid = lcid;
            this.presenceName = presenceText;
        }
    }
}