SMTP Attachments

VISTA - Premium Home - Delphi 2007 - Win 32

The code below is giving me an of :
TIdAttachment Undeclared Identifier

Can you tell me what I need to do to fix this?  It used to work in Delphi 7

  IdMsgSend.Clear;
  with IdMsgSend do
  begin
    Body.Text := 'i-SiteBackup Log Results Attached.';
    From.Text := edtEmail.Text;
    Recipients.EMailAddresses := edtEmail.Text;
    Subject := 'i-SiteBackup Log';
    Priority := TIdMessagePriority(1);
    ReceiptRecipient.Text := '';
    TIdAttachment.Create(MessageParts, lName);
  end;


Thanks for your help,
Dale