ASP.NET/VB.NET/SQL Server 2012 - Page keeps loading - asp.net

Question

I'm trying to run this code, and whenever I press the 'Register' button, nothing is happening (the page is like loading but stays on the same page)
Code:
Public Sub register()
Dim Username As String = txtUsername.Text
Dim Surname As String = txtSurname.Text
Dim Password As String = txtPassword.Text
Dim Name As String = txtName.Text
Dim Address1 As String = txtAddress1.Text
Dim Address2 As String = txtAddress2.Text
Dim City As String = txtCity.Text
Dim Email As String = txtEmail.Text
Dim Country As String = drpCountry.Text
Dim DOB As Date = calDOB.SelectedDate
Dim Occupation As String = txtOccupation.Text
Dim WorkLocation As String = txtWorkLocation.Text
Dim Age As Integer = Date.Today.Year - calDOB.SelectedDate.Year
Dim ProjectManager As String = "N/A"
Dim TeamLeader As String = "N/A"
Dim TeamLeaderID As Integer = "1"
Dim ProjectManagerID As Integer = "1"
Dim RegistrationDate As Date = DateTime.Today
Dim ContractType As String = "N/A"
Dim ContractDuration As Integer = 6
Dim Department As String = "N/A"
Dim conn As New SqlConnection("Data Source=BRIAN-PC\SQLEXPRESS;Initial Catalog=master_db;Integrated Security=True")
Dim registerSQL As SqlCommand
Dim sqlComm As String
Dim validateSQL As SqlCommand
Dim sqlValidate As String
sqlValidate = "SELECT * FROM users where username=" + txtUsername.Text.ToString
sqlComm = "INSERT INTO users(Username, Password, Name, Surname, Address1, Address2, " +
"City, Country, date_of_birth, age, Occupation, department, work_location, " +
"project_manager,team_leader, team_leader_id, project_manager_id, " +
"date_registration, contract_type, contract_duration) " +
"VALUES(#p1, #p2,#p3,#p4,#p5,#p6,#p7,#p8,#p9,#p10,#p11,#p12,#p13,#p14,#p15," +
"#p16,#p17,#p18,#p19,#p20)"
conn.Open()
validateSQL = New SqlCommand(sqlValidate, conn)
Dim dr As SqlDataReader = validateSQL.ExecuteReader()
If dr.HasRows = False Then
validateSQL = New SqlCommand(sqlValidate, conn)
validateSQL.CommandText = sqlValidate
Dim reader As SqlDataReader = validateSQL.ExecuteReader()
reader.Read()
registerSQL = New SqlCommand(sqlComm, conn)
registerSQL.Parameters.AddWithValue("#p1", Username)
registerSQL.Parameters.AddWithValue("#p2", Password)
registerSQL.Parameters.AddWithValue("#p3", Name)
registerSQL.Parameters.AddWithValue("#p4", Surname)
registerSQL.Parameters.AddWithValue("#p5", Address1)
registerSQL.Parameters.AddWithValue("#p6", Address2)
registerSQL.Parameters.AddWithValue("#p7", City)
registerSQL.Parameters.AddWithValue("#p8", Country)
registerSQL.Parameters.AddWithValue("#p9", DOB)
registerSQL.Parameters.AddWithValue("#p10", Age)
registerSQL.Parameters.AddWithValue("#p11", Occupation)
registerSQL.Parameters.AddWithValue("#p12", Department)
registerSQL.Parameters.AddWithValue("#p13", WorkLocation)
registerSQL.Parameters.AddWithValue("#p14", ProjectManager)
registerSQL.Parameters.AddWithValue("#p15", TeamLeader)
registerSQL.Parameters.AddWithValue("#p16", TeamLeaderID)
registerSQL.Parameters.AddWithValue("#p17", ProjectManagerID)
registerSQL.Parameters.AddWithValue("#p18", RegistrationDate)
registerSQL.Parameters.AddWithValue("#p19", ContractType)
registerSQL.Parameters.AddWithValue("#p20", ContractDuration)
registerSQL.ExecuteNonQuery()
conn.Close()
ElseIf dr.HasRows = True Then
lblUsername.Text = "That Username (" + txtUsername.Text + ") is already registered/taken."
lblUsername.Visible = True
conn.Close()
End If
End Sub
Button event handler:
Protected Sub btnRegister_Click(sender As Object, e As EventArgs) Handles btnRegister.Click
register()
End Sub
Is something wrong with the code?

Answer 1

From MSDN
While the SqlDataReader is being used, the associated SqlConnection is
busy serving the SqlDataReader, and no other operations can be
performed on the SqlConnection other than closing it. This is the case
until the Close method of the SqlDataReader is called. For example,
you cannot retrieve output parameters until after you call Close.
It appears that you have the SqlDataReader open when you try to execute the insert command.
I will try to close it before using the insert command
If dr.HasRows = False Then
dr.Close()
' The following lines are probably a remainder of a copy/paste operation'
' They are not needed and you should remove them'
'validateSQL = New SqlCommand(sqlValidate, conn)'
'validateSQL.CommandText = sqlValidate'
'Dim reader As SqlDataReader = validateSQL.ExecuteReader()'
'reader.Read()'
' Now execute the insert command
Also your command to check for the user presence, apart from perfomance arguments, is wrong because introduces Sql Injection possibilities.
Summarizing try with these changes....
sqlValidate = "SELECT * FROM users where username=#uname"
validateSQL = New SqlCommand(sqlValidate, conn)
validateSQL.Parameters.AddWithValue("#uname", txtUserName.Text)
Dim dr As SqlDataReader = validateSQL.ExecuteReader()
Dim userFound = dr.HasRows
dr.Close()
if userFound = False then
......