\documentclass[fleqn,leqno]{article}
\usepackage{hypertlabook}
\pdftitle{Control}
\begin{popup}
Typing \textsf{control+c} means holding down the
 \textsf{control} key and typing a lower-case letter~\textsf{c}.
  On Apple computers, use the \textsf{apple} key instead of
 \textsf{control}.
\end{popup}
\makepopup