ช่วยดู C# Win app บันทึกข้อมูลลง Database MDF ให้หน่อยครับ

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 System.Data.SqlServerCe;
using System.Data.SqlTypes;



namespace WindowsFormsApplication4
{
    public partial class สมัครสมาชิก : Form
    {
        public สมัครสมาชิก()
        {
            InitializeComponent();
        }

        private void สมัครสมาชิก_Load(object sender, EventArgs e)
        {
          
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(this.fname.Text))
            {
                MessageBox.Show("Please input (ชื่อ)");
                this.fname.Focus();
                return;
            }

            if (string.IsNullOrEmpty(this.lname.Text))
            {
                MessageBox.Show("Please input (นามสกุล)");
                this.lname.Focus();
                return;
            }
            SqlCeConnection myConnection = default(SqlCeConnection);
            
            string conStr=@"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\ทั่วไป\Documents\Visual Studio 2010\Projects\WindowsFormsApplication1\WindowsFormsApplication4\Database1.mdf;
            Integrated Security=True;User Instance=True";
            myConnection = new SqlCeConnection(conStr);
            myConnection.Open();
            SqlCeCommand myCommand = myConnection.CreateCommand();
            myCommand.CommandText = "INSERT INTO [member] ([mem_id], [hname], [fname], [lname], [address], [cellphone], [p_id], [lgroup], [land]) VALUES  " + " ('" + this.mem_id.Text + "','" + this.hname.Text + "','" + this.fname.Text + "','" + this.lname.Text + "','" + this.address.Text + "','" + this.cellphone.Text + "','" + this.p_id.Text + "','" + this.lgroup.Text + "','" + this.land.Text + "' ) ";
            myCommand.CommandType = CommandType.Text;
            myCommand.ExecuteNonQuery();
            myConnection.Close();

            MessageBox.Show("Save Successfully");

            this.Hide();
            สมัครสมาชิก f = new สมัครสมาชิก();
            f.Show();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            
        }

        
        }
    }