New Post: Import Products Issue

Thanks to ron and davi Sir,

                         After a 3 days continuous efforts to import products today I understand what exactly the csv file is but still I have problem. After changing the productcsv and  categorycsv like above I am getting the error like

System.NullReferenceException: Object reference not set to an instance of an object. at NEvoWeb.Modules.NB_Store.ImportCSV.buildCSVCategoryXML(PortalSettings PS, String[] CSVlines, String FieldDelimeter, String FieldQualifier, String FieldEscapedQualifier) at NEvoWeb.Modules.NB_Store.ImportCSV.ImportCSVProducts(PortalSettings PS, String ImportFile, Boolean UpdateExistingProductsFlg, Boolean CreateCategoriesFlg, String RowDelimeter, String FieldDelimeter, String FieldQualifier, String FieldEscapedQualifier)

please tell me which file I need to change is left. its urgent

please help