private void btnKaydet_Click(object sender, EventArgs e) { if (string.IsNullOrEmpty(txtUsername.Text) || string.IsNullOrEmpty(txtPassword.Text) || string.IsNullOrEmpty(txtEmail.Text)) { MessageBox.Show("Please enter your credentials.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } if (!db.SearchUserInfo(txtUsername.Text, txtPassword.Text)) { db.InsertUserInfo(txtUsername.Text, txtPassword.Text, txtEmail.Text); MessageBox.Show("You are signed up successfully!", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information); this.Close(); } else { MessageBox.Show("Sign up failed : The user already exists", "Message", MessageBoxButtons.OK, MessageBoxIcon.Error); } }