\documentclass{beamer}
\usepackage[dutch]{babel}
+\usepackage[labelformat=empty]{caption}
+\usepackage{booktabs}
+\usepackage{color}
+\usepackage{listings}
\usepackage{textgreek}
\title[\LaTeX workshop]{\url{linuxnijmegen.nl} \LaTeX workshop}
\author[Mart]{Mart Lubbers \footnote{\url{martlubbers.net}}}
\date{\today}
+\definecolor{mygreen}{rgb}{0,0.6,0}
+
+\lstset{%
+ language=[LaTeX]tex,
+ basicstyle=\small,
+ breaklines=true,
+ commentstyle=\color{mygreen}
+}
+
\AtBeginSubsection[]
{
\begin{frame}