My progress bar is not working properly it fills after getting the sucess message but I want showing progress bar with percentage and then sucess message

using System;
using System.ComponentModel;
using System.Windows.Forms;
using System.Threading;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            // get the backgroundworker to report the progress
            backgroundWorker1.WorkerReportsProgress = true;
            // Start the BackgroundWorker.
            backgroundWorker1.RunWorkerAsync();
        }


        private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            progressBar1.Value = e.ProgressPercentage;
        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            for (int i = 1; i <= 100; i++)
            {
                // Wait 100 milliseconds.
                Thread.Sleep(100);
                // Report progress.
                backgroundWorker1.ReportProgress(i);
            }
        }

        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            MessageBox.Show("Completed.");
        }
    }
}