xpath check if value-atribute is empty

Hello xml-dev members!

My name is Dominik Röth. I am working for Verivox and I am looking for the
answer to following question:

How can I check with an xpath expression that the value attribute of one
specific note is not empty?

Could anybody help me because I am completely new to the xml-stuff!

Thanks in advance.

Kind regards,

Dominik Röth

--
Dominik Röth
Produktentwicklung

Verivox GmbH
Hans-Böckler-Strasse 2
D-69115 Heidelberg

Fon: +49 (0) 6221 5028-156

For addressee only. E-mail may be falsified - the sender cannot be held
responsible for the integrity of this message.