Javascript debug project

A web page with a javascript section to make calculations and set colors based on those calculations mostly works... but am now noticing some times when it fails to paint the correct colors. It's rather simple in practice once you understand what it is supposed to do but might seem complicated until you gain an understanding. It's not a 1 hour debug session because you must first learn what it is intended to do and how it does it. Then it is probably 10 minutes to fix. Most Important -- I do NOT want to redesign it... rather I want to locate and fix the errors that are happening with the coloring without making it more complicated for me to parse and understand when you are done. In this example there are 3 fields. Thickness 1, Thickness 2 and Avg Thickness. Entered values for Thickness 1 and 2 are compared against the Spec and Data Limits. Spec Limits SLCL and SUCL (SpecLowerControlLimit and SUCL) Data Limits DLCL and DUCL (DataLowerControlLimit and DUCL) And depending upon what the outcome of the comparison is the form fields are colored differently. ====================== This is a small quick project for someone who knows their Javascript. All bids must come with: 1- a guarantee to complete the work in 4 days 2- carefully comment all changes you make to the code. Hopefully very few ;-) Attached is an html file with the javascript embedded into it and a second css file to compose the html page.