>Besides, I didn't see a problem in the code. As far, as I understand, there were no errors, but the code didn't remove double quotes from the file...

Hmmmm, looks fine to me. Dunno what the problem would be.

>Should I revert the code back to the original cursor idea?

As far as effeicent goes, I'd bet that the cursor idea is faster anyways, so yes. You could easily test it out.