Update button cannot function

Question

I'm a VB.NET programmer. I have created an update web form in ASP.NET having 3 fields; ID, Names, Email with 3 buttons cmdUpdate, cmdDelete and cmdCancel. All are executing except for the update button which is not executing, and I can't get an error message either. The code is below.

Protected Sub cmdUpdate_Click(sender As Object, e As EventArgs) Handles cmdUpdate.Click
    Dim conn As New SqlClient.SqlConnection("Data Source=(LocalDB)\MSSQLLocalDB;Initial Catalog=RegDb_backend;Integrated security=true;")
    Dim sql As String = "UPDATE tblClients SET ClientNames=@Names, ClientEmail=@Email WHERE ClientID=@ID;"
    Dim cmd = New SqlClient.SqlCommand(sql, conn)

    cmd.Parameters.Add(New SqlParameter("@Names", txtNames.Text.Trim()))
    cmd.Parameters.Add(New SqlParameter("@Email", txtEmail.Text.Trim()))
    cmd.Parameters.Add(New SqlParameter("@ID", Convert.ToInt64(txtID.Text.Trim)))

    Try
        conn.Open()
        cmd.ExecuteNonQuery()
        lblSuccess.Visible = True
        conn.Close()
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try

End Sub

I have tried researching and tweaking around with the code but the database won't get updated. Please help. Thank you.