Join two lines in sed

I was trying to load a CSV file into an Oracle database using SQL*Loader today and came across an issue where some of the fields contained CR within the data. Luckily each field is enclosed with double quotes ". Knowing this I was able to run the folling sed command which finds any lines that do not end with a double quote and joins them to the next line.

sed -e :a -e '/[^\"]$/N; s/[^\"]\n//; ta' _
  old_filename > new_filename

Just thought I'd share - someone might find it useful