Create asm

asm

@@ -0,0 +1,80 @@
+using System;
+using System.Data;
+using System.Data.SqlClient;
+using System.Windows.Forms;
+
+namespace SalesManagementSystem
+{
+    public partial class Login : Form
+    {
+        private string connectionString = @"Server=DINHKHIEM\SQLEXPRESS01;Database=hoangdinhkhiem;Trusted_Connection=True;";
+
+        public Login()
+        {
+            InitializeComponent();
+        }
+
+        // Executes when the login button is clicked
+        private void btnLogin_Click(object sender, EventArgs e)
+        {
+            string username = txtUsername.Text.Trim();
+            string password = txtPassword.Text;
+
+            if (string.IsNullOrEmpty(username) || string.IsNullOrEmpty(password))
+            {
+                MessageBox.Show("Please enter your username and password!", "Notice", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+                return;
+            }
+
+            try
+            {
+                using (SqlConnection conn = new SqlConnection(connectionString))
+                {
+                    conn.Open();
+                    string query = "SELECT COUNT(*) FROM Account WHERE Username = @Username AND Password = @Password";
+                    using (SqlCommand cmd = new SqlCommand(query, conn))
+                    {
+                        cmd.Parameters.Add("@Username", SqlDbType.NVarChar).Value = username;
+                        cmd.Parameters.Add("@Password", SqlDbType.NVarChar).Value = password;
+
+                        int result = (int)cmd.ExecuteScalar();
+
+                        if (result > 0)
+                        {
+                            MessageBox.Show("Login successful!", "Notice", MessageBoxButtons.OK, MessageBoxIcon.Information);
+                            MainForm mainForm = new MainForm();
+                            this.Hide();
+                            mainForm.Show();
+                        }
+                        else
+                        {
+                            MessageBox.Show("Username or password is incorrect!", "Notice", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                        }
+                    }
+                }
+            }
+            catch (SqlException sqlEx)
+            {
+                MessageBox.Show("Database error: " + sqlEx.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Unexpected error: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
+            }
+        }
+
+        // Open the registration form
+        private void btnRegister_Click(object sender, EventArgs e)
+        {
+            this.Hide();
+            Register registerForm = new Register();
+            registerForm.Show();
+        }
+
+        // Close the application
+        private void btnExit_Click(object sender, EventArgs e)
+        {
+            Application.Exit();
+        }
+    }
+}