Not Knowing How to Display Username After Login - vb.net

Question

I’m still stumbling with this page over and over again. Just couldn’t get the user’s Username (using email as the username) to display on mysupport.aspx page after she’s successfully logged in. The result should look like this with the email showing but it is not retrieving anything:
Email: barb#hotmail.com
Being an amateur, I know I’m missing a big piece of the puzzle but I don’t know what. Am I using the mailLBL.Text = User.Identity.Name.ToString() wrongly? Below are the code-behind:
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Data.SqlClient
Partial Class mysupport
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
Dim sConnection As New SqlConnection(ConfigurationManager.ConnectionStrings("TrackTicketsConnectionString2").ConnectionString)
sConnection.Open()
Dim cmdS As String = "Select Email from Users Where Deleted='N'"
Dim cmdCheckmail As New SqlCommand(cmdS, sConnection)
If Session("Ticket") IsNot Nothing Then
mailLBL.Text = User.Identity.Name.ToString()
Else
Response.Redirect("SignIn.aspx")
End If
End Sub
Protected Sub signinBTN_Click(ByVal sender As Object, ByVal e As EventArgs)
Session("Ticket") = Nothing
Response.Redirect("SignIn.aspx")
End Sub
End Class
Any help and guidance is truly appreciated!

Answer 1

What you could do first is study these links:
How to: Implement Simple Forms Authentication
How to use Sessions
There are several things wrong with this code.
Old Code:
Dim cmdS As String = "Select Email from Users Where Deleted='N'"
Dim cmdCheckmail As New SqlCommand(cmdS, sConnection)
If Session("Ticket") IsNot Nothing Then
mailLBL.Text = User.Identity.Name.ToString()
Else
Response.Redirect("SignIn.aspx")
End If
Corrected Code:
If Session("Ticket") Is Nothing Then
Response.Redirect("SignIn.aspx")
Else
Dim cmdS As String = "Select Email from Users Where Deleted='N' AND Username=#Username"
Dim cmdCheckEmail as new SqlCommand(cmdS, sConnection)
cmd.AddParameters(new SqlParameter("#UserName", SqlDbType.VarChar).Value = Session("Ticket")
Dim obj as Object = cmd.ExecuteScalar()
If obj isNot Nothing
mailLBL.Text = Convert.ToString(obj)
End If
End
I hope that helps.