Date range and the Ninox Id..

Hi, I have been struggling with the date range and Invoive Id system I created for some time. I have sorted the Invoice system, thanks to Steven and I may have sorted my date field. My latest problem I am now facing is if I want a report and select one of these feilds and filter with Ascend or Descend the "Ninox Id" over rides my request.  As this is a new system I have introduced to my staff and mistakes are being made, therfore records are being deleted and changed.When I am wanting to view reports with the Ascend or Descend selected the "Ninox Id" over rides my request and so am not getting information in a cronalogical order. Mistakes will always happen and need to be deleted so the Ninox Id will not always inline with the date. Any suggestions on how I can rectify this situation so I can view in order.

Regards

Michael