ผมต้องการให้พอโหลดหน้ามา textbox มันเป็นช่องว่างๆ ผมเลยใส่ textbok.text=""; แต่พอใส่ข้อมูลมันกับไม่บันทึก

 public partial class RegisterPage : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            txt_Auphor.Text = "";
            txt_EMail.Text = "";
            txt_HomeNum.Text = "";
            txt_Name.Text = "";
            txt_PassWord.Text = "";
            txt_Phone.Text = "";
            txt_Province.Text = "";
            txt_RePassWord.Text = "";
            txt_SurName.Text = "";
            txt_tambol.Text = "";
            txt_UserName.Text = "";
            txt_ZipCode.Text = "";


            int StartYear = 1900;
            int ThisYear = DateTime.Now.Year;
            DataTable dy = new DataTable("GenerateYear");
            DataColumn dyc = new DataColumn();
            DataRow dyr;
            dyc.DataType = System.Type.GetType("System.Int64");
            dyc.ColumnName="GenYear";
            dy.Columns.Add(dyc);
            for (int i = StartYear; i <= ThisYear; i++)
            {
                dyr = dy.NewRow();
                dyr[0] = i;
                dy.Rows.Add(dyr);
            }
            ddb_BirthYear.DataSource = dy;
            ddb_BirthYear.DataBind();
            ddb_BirthYear.SelectedValue = DateTime.Now.Year.ToString();
           

      }

        protected void bt_Save_Click(object sender, EventArgs e)
        { 
                  if(txt_UserName.Text=="" ||txt_UserName.Text == ""|| txt_PassWord.Text == "" ||txt_Name.Text == ""||txt_SurName.Text == ""||txt_HomeNum.Text == ""||txt_tambol.Text == ""|| txt_Auphor.Text == ""|| txt_ZipCode.Text == ""||txt_EMail.Text == ""||txt_Province.Text == ""||txt_Phone.Text == "")
                  {
                      MessageBox.Show("กรุณากรอกข้อมูลให้ครบ");
                      return;
                  }
                      if(txt_PassWord.Text!=txt_RePassWord.Text)
                        {
                            MessageBox.Show("กรุณากรอก Password ให้ตรงกัน");
                            return;
                        }
                      else if (fiUpload.HasFile)
                        {
                            try
                           {
                                  string user = txt_UserName.Text, pass = txt_PassWord.Text, name = txt_Name.Text, lastname = txt_SurName.Text, phone = txt_Phone.Text, mail = txt_EMail.Text, brith = "" + ddb_BirthDay.Text + "/" + ddb_BirthMonth.SelectedValue + "/" + ddb_BirthYear.Text;
                                  string HomeNum = txt_HomeNum.Text, Tambol = txt_tambol.Text, Amphor = txt_Auphor.Text, Province = txt_Province.Text, PostCode = txt_ZipCode.Text;
                                  string strConn = WebConfigurationManager.ConnectionStrings["ezyPetShopConnectionString2"].ConnectionString;
                                  SqlConnection Conn = new SqlConnection(strConn);
                                  Conn.Open();
                                  this.fiUpload.SaveAs(Server.MapPath("CustomerPic/"+user+ fiUpload.FileName ));
                                  string sqlregist1 = "INSERT INTO Customer(Username,Password,CustomerName,CustomerLastName,CustomerPhone,CustomerEMail,CustomerPic,CustomerBrith,HomeNum,Tambol,Amphor,Province,PostCode) VALUES (@user,@pass,@name,@lastname,@phone,@mail,'"+user+ fiUpload.FileName + "',@brith,@HomeNum,@Tambol,@Amphor,@Province,@PostCode) ";
                                  //string sqlregist2 = "INSERT INTO Customer_Address(Username,HomeNum,Tambol,Amphor,Province,PostCode) VALUES (@user,@HomeNum,@Tambol,@Amphor,@Province,@PostCode) ";
                                  SqlCommand com = new SqlCommand(sqlregist1, Conn);
                                  com.Parameters.AddWithValue("@user", user);
                                  com.Parameters.AddWithValue("@pass", pass);
                                  com.Parameters.AddWithValue("@name", name);
                                  com.Parameters.AddWithValue("@lastname", lastname);
                                  com.Parameters.AddWithValue("@phone", phone);
                                  com.Parameters.AddWithValue("@mail", mail);
                                  com.Parameters.AddWithValue("@brith", brith);
                                  //SqlCommand com2 = new SqlCommand(sqlregist2, Conn);
                                  //com.Parameters.AddWithValue("@user", user);
                                  com.Parameters.AddWithValue("@HomeNum", HomeNum);
                                  com.Parameters.AddWithValue("@Tambol", Tambol);
                                  com.Parameters.AddWithValue("@Amphor", Amphor);
                                  com.Parameters.AddWithValue("@Province", Province);
                                  com.Parameters.AddWithValue("@PostCode", PostCode);
                                  com.ExecuteNonQuery();
                                  //com2.ExecuteNonQuery();
                                  MessageBox.Show("บันทึกข้อมูลเรียบร้อย");
                           }
                          catch (Exception)
                           {
                          MessageBox.Show("ไม่สามารถใช้ Username นี้ได้");
                          }
                          
                       }
                       else
                       {
                           try
                           {
                                  string user = txt_UserName.Text, pass = txt_PassWord.Text, name = txt_Name.Text, lastname = txt_SurName.Text, phone = txt_Phone.Text, mail = txt_EMail.Text, brith = "" + ddb_BirthDay.Text + "/" + ddb_BirthMonth.SelectedValue + "/" + ddb_BirthYear.Text;
                                  string HomeNum = txt_HomeNum.Text, Tambol = txt_tambol.Text, Amphor = txt_Auphor.Text, Province = txt_Province.Text, PostCode = txt_ZipCode.Text;
                                  string strConn = WebConfigurationManager.ConnectionStrings["ezyPetShopConnectionString2"].ConnectionString;
                                  SqlConnection Conn = new SqlConnection(strConn);
                                  Conn.Open();
                                  string sqlregist1 = "INSERT INTO Customer(Username,Password,CustomerName,CustomerLastName,CustomerPhone,CustomerEMail,CustomerBrith,HomeNum,Tambol,Amphor,Province,PostCode) VALUES (@user,@pass,@name,@lastname,@phone,@mail,@brith,@HomeNum,@Tambol,@Amphor,@Province,@PostCode) ";
                                 // string sqlregist2 = "INSERT INTO Customer_Address(Username,HomeNum,Tambol,Amphor,Province,PostCode) VALUES (@user,@HomeNum,@Tambol,@Amphor,@Province,@PostCode) ";
                                  SqlCommand com = new SqlCommand(sqlregist1, Conn);
                                  com.Parameters.AddWithValue("@user", user);
                                  com.Parameters.AddWithValue("@pass", pass);
                                  com.Parameters.AddWithValue("@name", name);
                                  com.Parameters.AddWithValue("@lastname", lastname);
                                  com.Parameters.AddWithValue("@phone", phone);
                                  com.Parameters.AddWithValue("@mail", mail);
                                  com.Parameters.AddWithValue("@brith", brith);
                                  //SqlCommand com2 = new SqlCommand(sqlregist2, Conn);
                                 // com.Parameters.AddWithValue("@user", user);
                                  com.Parameters.AddWithValue("@HomeNum", HomeNum);
                                  com.Parameters.AddWithValue("@Tambol", Tambol);
                                  com.Parameters.AddWithValue("@Amphor", Amphor);
                                  com.Parameters.AddWithValue("@Province", Province);
                                  com.Parameters.AddWithValue("@PostCode", PostCode);
                                  com.ExecuteNonQuery();
                                  //com2.ExecuteNonQuery();
                                  MessageBox.Show("บันทึกข้อมูลเรียบร้อย");
                          }
                          catch (Exception)
                          {
                           MessageBox.Show("ไม่สามารถใช้ Username นี้ได้");
                          }
                         
                       }
       }

        
    }