opening new workbook and saving sheet

I am trying to write code which copies the activesheet (called "Data"), opens a new workbook, pastes the data into it and closes the new sheet as "sales 2008" followed by the date. What I have at the moment is:

Sub save_sheets_as_workbooks()
Dim d As String
Dim a As Integer

    Sheets("data").Select
    Sheets("data").copy
    d = ThisWorkbook.path & "\" & Workbooks("sales 2008.xls") & "  " & Day(Date) & "." & Month(Date) & "." & Year(Date) & ".xls"

    ActiveWorkbook.SaveAs d9
    ActiveWorkbook.Close
   '
End Sub

Unfortunately it's not working. It opens a new workbook (called book1) but then tries to close my existing workbook