private void button1_Click(object sender, EventArgs e) // them du lieu dang ky vao Database { label2.Text = null; label3.Text = null; label4.Text = null; if (textBox1.Text == "Username" || textBox1.Text == "") { label2.Text = "Please, enter username!"; } if (textBox2.Text == "Password" || textBox2.Text == "") { label3.Text = "Please, enter pasword!"; } if (textBox3.Text == "Email" || textBox3.Text == "") { label4.Text = "Please, enter email!"; } else if (!isEmail()) { label4.Text = "Email is invalid"; } if (label2.Text == "" && label3.Text == "" && label4.Text == "") { SqlConnection connect = QueryData.Connect_Server(); String permiss = "User"; String query = "INSERT INTO Account (UseName,PasswordID,Email,Permission) VALUES('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "' ,'" + permiss + "')"; bool kq = QueryData.ExecuteNonQueryUser(connect, query); // luu tai khoan nguoi dung if (kq) { MessageBox.Show("Resgister successfully !!!!"); label2.Text = null; label3.Text = null; label4.Text = null; } } }