กำลังทำขั้นตอนการ เปลี่ยนรหัสผ่าน อะครับ ช่วยดูทีครับ

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using MySql.Data.MySqlClient;

namespace StudentsEazy
{
    public partial class frmRepass : Form
    {
        MySqlConnection objConn = new MySqlConnection();
        MySqlCommand objCmd = new MySqlCommand();
        public frmRepass()
        {
            InitializeComponent();
        }

        private void btnSavePass_Click(object sender, EventArgs e)
        {
            String strConnString;
            strConnString = "Server=localhost;User Id=root; Password=123123; Database=db_project; Pooling=false; Allow Zero Datetime=false;";
            objConn = new MySqlConnection(strConnString);
            objConn.Open();
            string username = txtUser.Text;
            string password = txtCurrPass.Text;
            string newpass = txtNewPass.Text;
            string connewpass = txtConNewPass.Text;
            string selectString = "SELECT UserName,Password " + "FROM user " + "WHERE UserName = '" +txtUser + "' AND Password = '" + txtCurrPass + "'";
            MySqlCommand objCmd = new MySqlCommand(selectString, objConn);
            String strResult = String.Empty;
            strResult = (String)objCmd.ExecuteScalar();
            if (string.IsNullOrEmpty(this.txtUser.Text))
            {
                MessageBox.Show("Please input User_ID ?");
                this.txtUser.Focus();
                return;
            }
            if (string.IsNullOrEmpty(this.txtCurrPass.Text))
            {
                MessageBox.Show("Please input CurrentPassword ?");
                this.txtCurrPass.Focus();
                return;
            }
            if (string.IsNullOrEmpty(this.txtNewPass.Text))
            {
                MessageBox.Show("Please input NewPassword ?");
                this.txtNewPass.Focus();
                return;
            }
            if (string.IsNullOrEmpty(this.txtConNewPass.Text))
            {
                MessageBox.Show("Please input ConfirmNewPassword ?");
                this.txtConNewPass.Focus();
                return;
            }
            string sqlquery = "UPDATE user SET Password = " + txtConNewPass.Text + "WHERE Password = '" + txtCurrPass.Text + "'";
            objCmd = new MySqlCommand(sqlquery, objConn);
            objCmd.Connection = objConn;
            objConn.Close();
            MessageBox.Show("บักทึกรหัสผ่านใหม่ !!");
            Form f = new frmLogin();
            showForm(f);
        }
        private void showForm(Form f)
        {
            this.Hide();
            f.Show();
        }
    }
}