Countdown timer all button textbox not visible

This is my coding but countdown timer is not running and all textbox and labels are not visible..what is the error of this coding..


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Timers;


namespace timer1
{
    public partial class Form1 : Form
    {
        public int seconds;
        public int minutes;
        public int hours;
        public bool paused;




        public Form1()
        {
        }

        private void button1_Click(object sender, EventArgs e)
        {
            {
                if (paused != true)
                {
                    if ((textBox1.Text != "") && (textBox2.Text != "") && (textBox3.Text != ""))
                    {
                        timer1.Enabled = true;
                        button1.Enabled = true;
                        button2.Enabled = false;
                        button3.Enabled = true;
                        textBox1.Enabled = false;
                        textBox2.Enabled = false;
                        textBox3.Enabled = false;
                        textBox4.Enabled = false;
                        try
                        {
                            minutes = System.Convert.ToInt32(textBox2.Text);
                            seconds = System.Convert.ToInt32(textBox3.Text);
                            hours = System.Convert.ToInt32(textBox1.Text);
                        }
                        catch (Exception ex)
                        {
                            MessageBox.Show(ex.Message);
                        }
                    }
                    else
                    {
                        MessageBox.Show("Incomplete settings!");
                    }
                }
                else
                {
                    timer1.Enabled = true;
                    paused = false;
                    button2.Enabled = false;
                    button1.Enabled = true;
                }
            }

        }

        private void button2_Click(object sender, EventArgs e)
        {
             timer1.Enabled = false;
                paused = true;
                button1.Enabled = false;
                button2.Enabled = true;
        }
        private void button3_Click(object sender, EventArgs e)
        {
              // Stop the timer.
                paused = false;
                timer1.Enabled = false;
                button1.Enabled = false;
                button3.Enabled = false;
                button2.Enabled = true;
                textBox4.Clear();
                textBox3.Clear();
                textBox2.Clear();
                textBox1.Clear();
                textBox1.Enabled = true;
                textBox4.Enabled = true;
                textBox3.Enabled = true;
                textBox2.Enabled = true;
                textBox1.Enabled = true;
                label1.Text = "00";
                label2.Text = "00";
                label3.Text = "00";     
               

        }

        private void timer1_Tick(object sender, EventArgs e)
        {
              if ((minutes == 0) && (hours == 0) && (seconds == 0))
                {
                    // If the time is over, clear all settings and fields.
                    // Also, show the message, notifying that the time is over.
                    timer1.Enabled = false;
                    MessageBox.Show(textBox4.Text);
                    button1.Enabled = false;
                    button3.Enabled = false;
                    button2.Enabled = true;
                    textBox4.Clear();
                    textBox3.Clear();
                    textBox2.Clear();
                    textBox1.Enabled = true;
                    textBox4.Enabled = true;
                    textBox3.Enabled = true;
                    textBox2.Enabled = true;
                    textBox1.Enabled = true;
                    label1.Text = "00";
                    label2.Text = "00";
                    label3.Text = "00";
                }
                else
                {
                    // Else continue counting.
                    if (seconds < 1)
                    {
                        seconds = 59;
                        if (minutes == 0)
                        {
                            minutes = 59;
                            if (hours != 0)
                                hours -= 1;
     
                        }
                    else
                        {
                            minutes -= 1;
                        }
                    }
                    else
                        seconds -= 1;
                    // Display the current values of hours, minutes and seconds in
                    // the corresponding fields.
                    label1.Text = hours.ToString();
                    label2.Text = minutes.ToString();
                    label3.Text = seconds.ToString();
                   }
       }







    }
}