if (txtUsername.Text == username && txtPassword.Text == password)
            {
                MessageBox.Show("Login Successful!", "Successful", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);

                gbRegister.Enabled = false;
                gbConversion.Enabled = true;
                disableLogin();


                txtUsername.Clear();
                txtPassword.Clear();
            }

            {
                for (int i = 0; i < current; i++)

                    if (reg[i].username == txtUsername.Text && reg[i].password == txtPassword.Text)
                    {
                        MessageBox.Show("Login Successful!", "Successful", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
                        gbRegister.Enabled = false;
                        gbConversion.Enabled = true;
                        disableLogin();

                        txtFname.Clear();
                        txtLname.Clear();
                        txtRusername.Clear();
                        txtRpassword.Clear();

                        txtUsername.Clear();
                        txtPassword.Clear();
                    }
            }

            else
            {
                MessageBox.Show("Invalid Username or Password");
                txtUsername.Clear();
                txtPassword.Clear();
            }