Maybe you forgot to hit Post.

I thought of that, but even if I did, it wouldn't have saved it, would it?

 

Thanks for the help. I was able to pass the exam today after going over this last night. The circuit I had to build for the lab portion was close to this one except the first AND gate was replaced with an OR gate.

 

I've had similar things happen. There have been times when I've had to reboot the machine and was sure a post I was working on would be gone and yet when I opened that thread it was still in the Reply box. Apparently, at least sometimes, a draft of what we have typed for a response is stored somewhere. At times I'm almost convinced it has to be on the server. But it seems to be hit-and-miss.