Code source?

With excelEquations.xla downloaded from the above link (http://www.codecogs.com/pages/functions/download.php?dir=/components/excel_render~4cb8068b3f&file=excelEquations.xla~d0f625751f),

I keep getting this message when trying to Render Eqn both on new document and the example file provided in this website: "excelEquations_examples.xls could not be found. Check the spelling of the file name ..." Do I need that XLS file in addition to XLA file to run this Addins?

David