ASP.Net หน้า Register Password ต้องการเข้ารหัส MD5 ลง SQL Server Database

protected void btnRegister_Click(object sender, EventArgs e)
        {
            
            SqlConnection objConn = new SqlConnection();
            SqlCommand objCmd = new SqlCommand();
            String strConnString, strSQL;
            strConnString = "Data Source=NEWPROGRAMMER;Initial Catalog=customer;Integrated Security=True";
            strSQL = "INSERT INTO register (username,lastname,password,address,tel,mobile,email) " +
            " VALUES " +
            " ('" + this.txtUsername.Text + "','" + this.txtLastname.Text + "','" + this.txtPassword.Text + "', " +
            " '" + this.txtAddress.Text + "','" + this.txtTel.Text + "','" + this.txtMobile.Text + "','" + this.txtEmail.Text +"' )";
            objConn.ConnectionString = strConnString;
            objConn.Open();
            objCmd.Connection = objConn;
            objCmd.CommandText = strSQL;
            objCmd.CommandType = CommandType.Text;
            this.pnlRegister.Visible = false;

            try
            {
                objCmd.ExecuteNonQuery();
                this.lblStatus.Text = "Record Inserted";
                this.lblStatus.Visible = true;
               
            }
            catch (Exception ex)
            {
                this.lblStatus.Visible = true;
                this.lblStatus.Text = "Record can not insert Error (" + ex.Message + ")";
            }
            objConn.Close();
            objConn = null;

           // this.pnlRegister.Visible = false;
            this.pnlFinish.Visible = true;