Ok, note to self & all, COPY a screen before you customize it so you have the original (presumably working) screen before you hose it up. Sorry I didn't do that and now I can't enter data on my customized Time Tracking screen (cas account). When I click on "Save" a box pops up that says an error has occurred and an email message has been sent to the Method team.
After a few minutes thought, I created a copy of the Time Tracking Screen by importing it from the Method library and was back in business, able to enter time, albeit on the originally formatted screen, not on my customized one.
Can the team tell me what is wrong with my customized Time Entry screen?
Also, can a field hold a calculated value? (How?) My client wants a markup field, so I thought I'd also need a field to hold the new total billable time=duration+-markup. Then I would need to be able to pull the calculated time to an invoice instead of the original duration field entry.