entering data in excel sheet trough Vb application form

[zoomtronic]

I did following code, ad this is pretty what i need, but i need more control over it,
actually i need ID, i meant to put another text box and to link it with column F for instance,
this will provide me back info about row which application is writing to. Because i don't know which row
is already taken, back info regarding ID is required.
any idea how to read that column and display next empty ID row?

Thanks in advance

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim xlApp As Excel.Application
        Dim xlWorkBook As Excel.Workbook
        Dim xlWorksheet As Excel.Worksheet
        Dim lastRow As Long

        xlApp = New Excel.Application
        xlWorkBook = xlApp.Workbooks.Open("C:\file.xlsx")
        xlWorksheet = xlWorkBook.Worksheets(1)
        xlApp.Visible = False

        lastRow = xlWorksheet.Range("A" & xlApp.Rows.CountLarge).End(Excel.XlDirection.xlUp).Row + 1

        With xlWorksheet
            .Range("A" & lastRow).Value = Me.TextBox1.Text
            .Range("B" & lastRow).Value = Me.TextBox2.Text
            .Range("C" & lastRow).Value = Me.TextBox3.Text
            .Range("D" & lastRow).Value = Me.TextBox4.Text
            .Range("E" & lastRow).Value = Me.TextBox5.Text
            .Range("F" & lastRow).Value = Me.TextBox6.Text
        End With

        xlWorkBook.Save()
        xlWorkBook.Close()

        releaseObject(xlWorkBook)
        releaseObject(xlWorksheet)
        xlApp.Quit()
        releaseObject(xlApp)
    End Sub
    Private Sub releaseObject(ByVal obj As Object)
        Try
            System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
            obj = Nothing
        Catch ex As Exception
            obj = Nothing
        Finally
            GC.Collect()
        End Try

    End Sub



    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        'clears text boxes
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""
        TextBox4.Text = ""
        TextBox5.Text = ""
        TextBox6.Text = ""
    End Sub