Advice for vb.net web application structure with code generator - refactoring, rewrite, change ORM?

Hello Experts -

I have been working on a web application for the past year and I have been using a code generator that I wrote that creates all the necessary classes, web fields, javascript code, code behind, data access and stored procedures, generated from a database table. This application was originally intended to be a small interim solution between my client's company use of spreadsheets, and a full blown enterprise application. Turns out now they want to expand the application I've been working on for their enterprise application, and I'm nervous about handing it off to other developers. I'm in a quandry since I'm not deeply trained in .net development, and I'm not sure what the best solution is at this point. Would you share with me your recommendations on what you might do in this situation? The site has become quite large now, so I'm wondering if refactoring the code would be enough, or converting to Entity Framework for the database/stored procedure, or using a different ORM would be a good idea?  I'm using DataReaders to load classes from the database records, then then looping through those class records to write literal HTML code in the code behind, which I am tying to form objects (literal). The reason I wanted to use data readers and JSON Ajax is its speed and leanness, not depending on Microsoft's built in objects which I understand tend to slow down performance generally. The upside is anyone who uses my generator can output all the code necessary for any database calls and presentation very quickly. The downside is there's a lot of code generated. Here's the architecture of the site as is:

Web Forms (aspx) referencing JSON Ajax calls to Code Behind
>
Code Behind (aspx.vb)
>
Entity Class
>
Abstract Data Provider Class (for optionally switching data store)
> 
SQL Server Data Provider Class
>
SQL Server Stored Procedures

Thanks for whatever suggestions/recommendations you have. Is this structure so dated that other developers would shoot me for having to wade through all these layers, or is this a workable code base?

Thanks,
Steve



Here is a sample of the typical patter I'm using throughout the site:

################# JAVASCRIPT (on .aspx page)  #################

function InsUpd_Person() {
	// … set vars to form field vals
	var first_name = document.getElementById("txtFirstName").value;
	var person = new clientPerson(person_id, person, company_id,  department_id,  first_name, last_name, email);
	
	// invoke PageMethods 
	var serializedPerson = Sys.Serialization.JavaScriptSerializer.serialize(person);
	PageMethods.InsertUpdate_Person(serializedPerson, callBackUpdatePerson);
}


################# CODE BEHIND #################

<WebMethod()> _ 
<ScriptMethod()> _ 
Public Shared Function InsertUpdate_Person(ByVal jsonPerson As String) As String

	Dim serializer As New JavaScriptSerializer() 
	Dim oPerson As Person = serializer.Deserialize(Of Person)(jsonPerson)

	objPerson = New Person
	objPerson.Person_ID = oPerson.Person_ID 
	objPerson.Company_ID = IIf(oPerson.Company_ID = "-1", 0, oPerson.Company_ID)
	objPerson.Department_ID = IIf(oPerson.Department_ID = "-1", 0, oPerson.Department_ID)
	objPerson.First_Name = ToNothing(oPerson.First_Name)
	objPerson.Last_Name = ToNothing(oPerson.Last_Name)
	objPerson.Email = ToNothing(oPerson.Email)
	SiteProvider.Company.UpdatePerson(objPerson)
End Sub



################# CLASS  #################

<Serializable()> _
Public Class Person

Public Sub New()
	End Sub
	Public Sub New(ByVal vPerson_ID As Integer, _
	ByVal vRecCount As Integer, _
	ByVal vCompany_ID As Integer, _
	ByVal vDepartment_ID As Integer, _
	ByVal vFirst_Name As String, _
	ByVal vLast_Name As String, _
	ByVal vEmail As String)
		Me.Person_ID = vPerson_ID
	Me.RecCount = vRecCount
	Me.Company_ID = vCompany_ID
	Me.Department_ID = vDepartment_ID
	Me.First_Name = vFirst_Name
	Me.Last_Name = vLast_Name
	Me.Email = vEmail
End Sub

Private _Person_ID As Integer = Nothing
Public Property Person_ID() As Integer
	Get
		Return _Person_ID
	End Get
	Set(ByVal Value As Integer)
		_Person_ID = Value
	End Set
End Property
	Private _Company_ID As Integer = Nothing 
Public Property Company_ID() As Integer
	Get
		Return _Company_ID
	End Get
	Set(ByVal Value As Integer)
		_Company_ID = Value
	End Set
End Property
	Private _Company As String = ""
Public Property Company() As String
	Get
		Return _Company
	End Get
	Set(ByVal Value As String)
		_Company = Value
	End Set
End Property
	Private _Department_ID As Integer = Nothing 
Public Property Department_ID() As Integer
	Get
		Return _Department_ID
	End Get
	Set(ByVal Value As Integer)
		_Department_ID = Value
	End Set
End Property
	Private _Department As String = ""
Public Property Department() As String
	Get
		Return _Department
	End Get
	Set(ByVal Value As String)
		_Department = Value
	End Set
End Property
	Private _First_Name As String = "" 
Public Property First_Name() As String
	Get
		Return _First_Name
	End Get
	Set(ByVal Value As String)
		_First_Name = Value
	End Set
End Property
	Private _Last_Name As String = "" 
Public Property Last_Name() As String
	Get
		Return _Last_Name
	End Get
	Set(ByVal Value As String)
		_Last_Name = Value
	End Set
End Property
	Private _Email As String = "" 
Public Property Email() As String
	Get
		Return _Email
	End Get
	Set(ByVal Value As String)
		_Email = Value
	End Set
End Property
End Class



################# ABSTRACT PROVIDER CLASS   #################
Public MustOverride Function InsertPerson(ByVal Person As Person) As Integer



################# SQL STORED PROCS ACCESS CLASS  #################
Public Overloads Overrides Function InsertPerson(ByVal oPerson As Person) As Integer
	Using cn As New SqlConnection(Me.ConnectionString)
	Dim cmd As New SqlCommand("wsa_Person_i", cn)
	cmd.CommandType = CommandType.StoredProcedure
	cmd.Parameters.Add("@Company_ID", SqlDbType.Int).Value = oPerson.Company_ID
	cmd.Parameters.Add("@Department_ID", SqlDbType.TinyInt).Value = oPerson.Department_ID
	cmd.Parameters.Add("@First_Name", SqlDbType.VarChar).Value = oPerson.First_Name
	cmd.Parameters.Add("@Last_Name", SqlDbType.VarChar).Value = oPerson.Last_Name
	cmd.Parameters.Add("@Email", SqlDbType.VarChar).Value = oPerson.Email
	cmd.Parameters.Add("@Person_ID", SqlDbType.Int).Direction = ParameterDirection.Output
	cn.Open()
	Dim ret As Integer = ExecuteNonQuery(cmd)
	Return DirectCast(cmd.Parameters("@Person_ID").Value, Integer)
	End Using
End Function




################# STORED PROCEDURE  #################

CREATE PROCEDURE wsa_Person_i
(
	@Company_ID int = Null,
	@Department_ID tinyint = Null,
	@First_Name varchar(50) = Null,
	@Last_Name varchar(50) = Null,
	@Email varchar(150) = Null,
	@Person_ID int OUTPUT
)
AS

	BEGIN TRAN
	INSERT Person
	(
		Company_ID,
		Department_ID,
		First_Name,
		Last_Name,
		Email
	)
	VALUES
	(
		@Company_ID,
		@Department_ID,
		@First_Name,
		@Last_Name,
		@Email
	)
	IF @@error <> 0
	BEGIN
		ROLLBACK TRAN
		RAISERROR ('An error occurred adding to Person',1,1)
		RETURN
	END
	Set @Person_ID = CAST(SCOPE_IDENTITY() AS INT)

	COMMIT TRAN

Return