String comparison returns false, but I don't know why

Hi all

I'm hoping someone can see the error in the code below. I cannot. This very simple script is supposed to look at the last character of every line and, if it's a space, remove underlining from the space. It worked until I added the if statement (which I had to do because without it, the script was removing the underlining from a letter that preceded an automatic hyphen). As its written now, it fails to find the spaces at the end of lines.

I'm grateful (as always) for any help. Here's the script.