Duplicate records created on page load vb.net - asp.net

Question

I trying to figure out why my code in inserting two records into the database when it executes? the CreateEnrollment Sub executes fine, however the results insert 2 sometimes 3 records ranging from 1-10 seconds apart, depending on remote server load. I first thought it might be the IsPostBack problem but adding the If Not Page.IsPostBack Then did not resolve.
Dim FailedMessage As String = "This COPDI (On-Line) user failed: "
Dim PassedMessage As String = "This COPDI (On-Line) user passes: "
Dim ClassName As String = "COPDI (FAILED)"
Dim SendMailAddress As String = "myEmailAddress.com"
Dim SubsiteConnString As String = "Subsite_appSettings"
Dim MainsiteConnString As String = "SubsiteConn"
Dim RecordsReturned As Integer = 0
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim UserName As String = User.Identity.Name()
Dim userID As Integer = GetUID(UserName)
Dim ClassDate As Date = DateTime.Now.AddHours(3).ToShortDateString
Dim ClassTime As String = DateTime.Now.AddHours(3). ToShortTimeString
If Not Page.IsPostBack Then
If Request.QueryString("code") = 1111 Then
RecordsReturned = RecordExist(UserName)
CreateEnrollment(UserName, ClassDate, ClassTime, ClassName, userID)
UpdateLastActivityDate(UserName)
If RecordsReturned < 3 Then
Response.Redirect("~/transcript.aspx" & "?code=" & RecordsReturned)
Else
Response.Redirect("~/transcript.aspx" & "?code=" & "more_than_three")
End If
End If
End If
End Sub
Public Sub CreateEnrollment(ByVal UserName As String, ByVal ClassDate As Date, ByVal ClassTime As String, ByVal ClassName As String, ByVal UID As Integer)
Dim connStr As String = ConfigurationManager.AppSettings.Get(SubsiteConnString)
Dim conn As New Data.OleDb.OleDbConnection(connStr)
Try
conn.Open()
Dim sql As String = "INSERT INTO EnrollmentsTbl (" & _
"[UserName],[SubmitTime],[ClassTime],[ClassDate],[Enrolled],[ClassName],[Instructor],[DateCompleted],[Completed],[WaitListed],[UID]) " & _
"VALUES (#UserName, #SubmitTime, #ClassTime, #ClassDate, #Enrolled, #ClassName, #Instructor, #DateCompleted, #Completed, #WaitListed, #UID) "
Dim comm As New Data.OleDb.OleDbCommand(sql, conn)
comm.Parameters.AddWithValue("#UserName", UserName)
comm.Parameters.AddWithValue("#SubmitTime", DateTime.Now.AddHours(3).ToString())
comm.Parameters.AddWithValue("#ClassTime", ClassTime)
comm.Parameters.AddWithValue("#ClassDate", ClassDate)
comm.Parameters.AddWithValue("#Enrolled", True)
comm.Parameters.AddWithValue("#ClassName", ClassName)
comm.Parameters.AddWithValue("#Instructor", "On-line")
comm.Parameters.AddWithValue("#DateCompleted", DateTime.Now.AddHours(3).ToString)
comm.Parameters.AddWithValue("#Completed", False)
comm.Parameters.AddWithValue("#WaitListed", False)
comm.Parameters.AddWithValue("#UID", UID)
Dim result As Integer = comm.ExecuteNonQuery()
Catch ex As Exception
Response.Write(ex)
Finally
conn.Close()
End Try
End Sub
Public Function RecordExist(ByVal username As String) As Integer
Dim connStr As String = ConfigurationManager.AppSettings.Get(SubsiteConnString)
Dim conn As New Data.OleDb.OleDbConnection(connStr)
Dim sql As String = "SELECT COUNT(*) FROM EnrollmentsTbl " & _
"WHERE [UserName] = """ & username & """ AND ClassName LIKE """ & ClassName & """ AND [Completed] = 0 AND [Enrolled] = -1"
Dim DBCommand As New Data.OleDb.OleDbCommand(sql, conn)
Try
conn.Open()
Dim RecordCount As Integer = CInt(DBCommand.ExecuteScalar())
conn.Close()
Return RecordCount
Catch ex As Exception
Response.Write(ex)
Finally
conn.Close()
End Try
End Function
Public Function GetUID(ByVal username As String) As Integer
Dim xUserName As String = User.Identity.Name()
If (Not xUserName="") Then
Dim objConn As Data.OleDb.OleDbConnection
Dim objCmd As Data.OleDb.OleDbCommand
Dim objRdr As Data.OleDb.OleDbDataReader
Dim userAN As String
Dim strConnection As String = ConfigurationManager.ConnectionStrings("TechTrainingConn").ToString
objConn = New Data.OleDb.OleDbConnection(strConnection)
objCmd = New Data.OleDb.OleDbCommand("SELECT * FROM UsersDataTbl WHERE [UserName] = """ & xUserName & """", objConn)
Try
objConn.Open()
objRdr = objCmd.ExecuteReader()
While objRdr.Read()
userAN = objRdr.Item("UID")
End While
objRdr.Close()
objConn.Close()
Session("userID") = userAN
Return userAN
'Response.Write(Session("userAN") & " - " & xUserName)
Catch ex As Exception
Response.Write(ex)
Finally
objConn.Close()
End Try
End If
End Function

Answer 1

What aspx page is this supporting? I noticed you have a redirect to transcript.aspx, is this code for that page? If so that would explain the multiple page loads. Response.Redirect is not a postback so it's going to fall into recordReturned and CreateEnrollment methods again, especially if you are passing the &code=1111 in the URL querystring