Creating an automatic Check list of errors

I am developing a Check list to highlight errors within tables of data. There will be multiple worksheets of varing length within the spreadsheet. In this example sheet I have included one sheet of a short length.

On the "Sheet 1" there should be no difference between the values in Column J and column I. I would like a Macro (I think) to produce a list in Cell F of the check sheet of all entries within column A, on sheet 1, where there is a difference.

Any help would be much appreciated.

See attached workbook.