Add-in to Check for Double Resource Booking

public partial class ThisAddIn
    {
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            // attach to the Item Send Event
            Application.ItemSend += new Outlook.ApplicationEvents_11_ItemSendEventHandler(Application_ItemSend);
        }

        void Application_ItemSend(object Item, ref bool Cancel)
        {
            // try to cast to a Meeting Item
            Outlook.MeetingItem meet = Item as Outlook.MeetingItem;
            if (meet != null) // is it a meeting item - not null
            {
                // load the list of conference rooms from the install folder
                List<string> rooms = new List<string>();
                string path = System.Reflection.Assembly.GetExecutingAssembly().Location + "\\MeeingRooms.txt";
                StreamReader sr = new StreamReader(path);
                while (!sr.EndOfStream)
                {
                    // save as lowercase -- we will compare this way
                    rooms.Add(sr.ReadLine().ToLower());
                }

                int cnt = 0;
                // no loop through all the recipients
                foreach (Outlook.Recipient r in meet.Recipients)
                {
                    // if the recipient is in the List of rooms we count it
                    if (rooms.Contains(r.Name.ToLower()))
                        cnt++;

                    // now if we get more than one -- we have a problem
                    if (cnt > 1)
                    {
                        // notify the user they are about to send a meeting request
                        // that will book more than one room
                        DialogResult result = MessageBox.Show("You have more than one conference room on " +
                                                          "this meeting request. \n\n" +
                                                          "Are you sure you want to continue?", "Resource Conflict",
                                                          MessageBoxButtons.YesNoCancel, MessageBoxIcon.Hand);
                        // if the user hits cancel or no, we will
                        // cancel the send
                        if (result != DialogResult.Yes)
                            Cancel = true;
                        else
                            // otherwise, allow it
                            Cancel = false;

                        // exit for loop
                        break;
                    }
                    else
                    {
                        Cancel = false;
                    }
                }
            }
            else
            {
                Cancel = false;
            }
        }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using Outlook = Microsoft.Office.Interop.Outlook;
using Office = Microsoft.Office.Core;
using System.Windows.Forms;
using System.IO;