VB.net check username is available

Hello,

I'm trying to check my mysql database to see if users are in the database in real time.

Green if username is not user - red if not.

code is

 <asp:ScriptManager ID="ScriptManager1" runat="server"> </asp:ScriptManager>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
   <ContentTemplate>
       UserName: 
        <asp:TextBox ID="txtUName" runat="server" 
                   ontextchanged="txtUName_TextChanged" 
                   AutoPostBack="True"/>
        
       <asp:Image ID="imgUsr" runat="server" Visible="false"/>
        <asp:Label ID="lblUsr" runat="server"/>
        
        
    </ContentTemplate>
    </asp:UpdatePanel>

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Imports System.Data
Imports MySql.Data.MySqlClient

Partial Class signup
    Inherits System.Web.UI.Page
	Dim MysqlConn As MySqlConnection
Dim con As New mySqlConnection(ConfigurationManager.ConnectionStrings("dbconnection").ConnectionString)
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    End Sub


Protected Sub txtUName_TextChanged(sender As Object, e As EventArgs)
 If txtUName.Text <> String.Empty Then
 
  Dim strSelect As String = "SELECT COUNT(*) FROM members WHERE Username = txtUName.Text.Trim().ToString()"
  
  Dim cmd As New mySqlCommand(strSelect, con)

  
  cmd.Parameters.Add(txtUName.Text.Trim().ToString())
  con.Open()
  Dim result As Integer = DirectCast(cmd.ExecuteScalar(), Int32)
  con.Close()

  If result >= 1 Then
   imgUsr.ImageUrl = "unavailable.png"
   imgUsr.Visible = True
   lblUsr.Text = "Username not available"
   lblUsr.ForeColor = System.Drawing.Color.Red
  Else
   imgUsr.ImageUrl = "tick.png"
   imgUsr.Visible = True
   lblUsr.Text = "Available"
   lblUsr.ForeColor = System.Drawing.Color.Green
  End If
 End If

End Sub

    
End Class

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but it does nothing live??? no red or green

http://runningprofiles.com/signup.aspx