Text Formatting ⇒ Minus in code listing

[trophi20]

I've got a question, topic is the code listing.
How is it possible to write a minus (-) in a code listing?

I'm using Texmaker and MikTex.

Here's a example:

Code: Select all

\documentclass{article}
\usepackage{listings}  

\begin{document}
\begin{lstlisting}
    a = 10;
    a = 10 - 2;
\end{lstlisting}
\end{document}

The error:

Code: Select all

! Undefined control sequence.
<argument> \textminus

Does somebody know this error?

EDIT

Escape text solves this problem. But is this a good way?

[rais]

The code provided does not result in the error shown.
And why should it? A - in the text is just a hyphen, not a minus sign...
You seem to be doing something else than shown.

KR
Rainer