LyX ⇒ Nomenclature with units

[Thorondor]

Hi people!

I'm trying to make a nomenclature with the units after the description. The Lyx wiki says:

Adding Units and lining them up on the right

The code shown here defines a new command (\nomunit) which can be used in the description box following the description. Usage is as \nomunit{unit}, or my preferred \nomunit{[unit]} to encapsulate the units in square brackets.
\newcommand{\nomunit}[1]{%
\renewcommand{\nomentryend}{\hspace*{\fill}#1}}

Do I paste this in the Description box every time? Because testing this with a description box containing

time
\newcommand{\nomunit}[s]{%
\renewcommand{\nomentryend}{\hspace*{\fill}#1}}

gives me the error

LaTeX Error: \begin{thenomenclature} on input line 1 ended by \end{document}.

What am I doing wrong?
I wish there were some examples on the wiki.

[abelle]

Put it in the Document>Settings>LaTeX Preamble.