Not enough information.
Is this a Access web page or a form or report?
What is the data behind the form/report/page?
You can check the dates against today's date, or you can check for the date difference between the date of the complaint and today's date and no data in the Date Resolved field using code, and based on your parameters you can format text. If this is a web page, you can create a Flash warning, and drop it on the page if the parameters are passed, etc.
There are lots of ways to do this but they depend on your data and what you want to do it on.