ASP form modified with VBScript

I have a form ([login to view URL]) that has a row at the bottom of the screen. This page requires a user to enter a start time/end time. The user then selects a job from a dropdown list. This will automatically populate the TimePerSqFT box. The user then enters a number in the SqFT box and this would be multiplied by TimePerSqFT and a start time/end time will automatically populate in the appropriate boxes on the same row. The user then clicks "Add Item" and the page reloads with the previous data and a new blank row. The PROBLEM: The function I have to automatically update the start/end time boxes only works for the current row. I would like to be able to change a value in any box and see all the calculated times change on the page and once the user is done be able to save the data in my Access database. I have attached a screenshot of the current page with just the first blank row (row #2). As a user clicks "Add Item" it could grow to as many as 50 rows or as little as 2. Once all the rows are on the screen if a user manually changes any box, ALL the boxes need to be recalculated. This is only the first of about 12 "mini-projects" that I will be contracting out. Examples of your work that are similar to this project would be best.