Depends on what he means by a "blank string"
My solution said that nulls are not blanks. If you are willing to accept them, then just:
TRIM(x) IS NULL
Cheers,
Ben
"good ideas and bad code build communities, the other three combinations do not"
- [link|http://archives.real-time.com/pipermail/cocoon-devel/2000-October/003023.html|Stefano Mazzocchi]