javascript copy fields, and update with asp

I have a page here designed in vbscript/asp <[login to view URL]> the client, needs to update 26,000 records, but the vast majoirty of them are similar, so I need a javascript function that will copy the value from the previous field, and the can continue to press to copy, all the way down the page (if need be), then a multi-update fuction in asp at the button, to save all the value. All should be apparant when you look at the like above.