While working on my scarf, I suddenly realized that I had skipped a row and the result was that the front design was appearing on the back of the scarf!!
So, I looked up how to frog on the interweb, and nervously set to work.
Long story short: it worked. I used some fingering yarn and a tapesty needle to keep from losing the stitches. (I found the suggestion on the Internet.)
The scarf us about nine inches long. Fifty inches to go!! Whoo!!