ASP.NET

<input type="submit" name="ctl00$grdConfig$ctl04$btnAdd" value="Add New" id="btnAdd" wtx-context="FC3AB902-A74E-4209-8E0D-9F9AC5F15021">

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
       If Page.IsPostBack Then
           ClientScript.RegisterHiddenField("isPostBack", "1")
       End If
   End Sub

var isPostBackObject = document.getElementById('isPostBack');
            if (isPostBackObject != null) {
             //Do something
            }

Dim AdminFinalFilename As New List(Of String)

Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click


        finalfilename = DateTime.Now.ToString("ddMMyyhhmm") + "_" + FileUpload1.FileName
       
            AdminFormFilename.Add(finalfilename)


End Sub

 Protected Sub FormSubmit_Click(sender As Object, e As EventArgs) Handles FormSubmit.Click


If AdminFinalFilename Is Nothing Then

        Else

            Dim i As Integer
            For i = 0 To AdminFinalFilename.Count - 1

                Dim y As New accessadminreq

                y.InsertAdminUpload(FormID, (AdminFinalFilename.Item(i)))

            Next i

        End If


End Sub