Untitled

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;

namespace show8
{
    public partial class Form1 : Form
    {
        int recordcount = 0;
        string[,] List = new string[100,4];
        public Form1()
        {
            InitializeComponent();
            comboBox1.Text = "History";
            comboBox1.Items.Add("English");
            comboBox1.Items.Add("Math");
            comboBox1.Items.Add("Khmer");
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string id = txtID.Text;
            string name = txtName.Text;
            string type = txtType.Text;
            string title = comboBox1.Text;

            List[recordcount, 0] = id;
            List[recordcount, 1] = name;
            List[recordcount, 2] = type;
            List[recordcount, 3] = title;
            recordcount++;
            listBox1.Items.Add($"{txtID.Text} | {comboBox1.SelectedItem} | {txtName.Text} | {txtType.Text}"); ;

        }

        private void button3_Click(object sender, EventArgs e)
        {
            string bookID = txtID.Text.Trim();
            if (string.IsNullOrEmpty(bookID))
            {
                MessageBox.Show("Please enter a Book ID to delete.", "Error");
                return;
            }

            for (int i = 0; i < recordcount; i++)
            {
                if (List[i, 0] == bookID)
                {
                    for (int j = i; j < recordcount - 1; j++)
                    {
                        List[j, 0] = List[j + 1, 0];
                        List[j, 1] = List[j + 1, 1];
                        List[j, 2] = List[j + 1, 2];
                        List[j, 3] = List[j + 1, 3];
                    }

                    recordcount--;

                    comboBox1.Items.RemoveAt(i);

                    MessageBox.Show($"Book with ID '{bookID}' deleted successfully.", "Success");
                }
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string bookID = txtID.Text;

            for (int i = 0; i < recordcount; i++)
            {
                if (List[i, 0] == bookID)
                {
                    MessageBox.Show($"Record found:\nBook ID: {List[i, 0]}\nTitle: {List[i, 1]}\nBorrower Name: {List[i, 2]}\nDate: {List[i, 3]}", "Search Result");
                }
            }
        }
    }
    
}