SL::DB::Manager::InvoiceItem->delete_all( all => 1);
SL::DB::Manager::Invoice->delete_all( all => 1);
SL::DB::Manager::Customer->delete_all( all => 1);
SL::DB::Manager::InvoiceItem->delete_all( all => 1);
SL::DB::Manager::Invoice->delete_all( all => 1);
SL::DB::Manager::Customer->delete_all( all => 1);