LaTeX Warning: Citation 'author2012' on page 1 undefined on input line 15 [closed]

How do you correct an undefined citation? I've clicked the BibTex option several times to let Latex automatically recognize the new references, but this isn't working.

\documentclass[12pt,a4paper]{report}
\usepackage{natbib}
\begin{document}
\section{Introduction}
\label{sec:intro}
\subsection{A}
Text with \cite{hatcher2008}
\bibliographystyle{plain}
\bibliography{bibfile}
\end{document}


Addendum: Here's an excerpt from the .bib file:

@article{hatcher2008curcumin}
title={Curcumin: from ancient medicine to current clinical trials},
author={Hatcher, H. and Planalp, R. and Cho, J. and Torti, FM and Torti, SV},
journal={Cellular and Molecular Life Sciences},
volume={65},
number={11},
pages={1631--1652},
year={2008},
publisher={Springer}

-

closed as too localized by Martin Schröder, lockstep, Andrew Swann, Marco Daniel, ThorstenOct 22 '12 at 10:59

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

Welcome to TeX.sx! Please add a minimal working example (MWE) that illustrates your problem. –  Benedikt Bauer Oct 22 '12 at 6:30
\documentclass[12pt,a4paper]{report} \usepackage{graphicx}{options}{natbib} \pagestyle{headings} \newcommand{\HRule}{\rule{\linewidth}{0.5mm}} \begin{document} \input{./title.tex} \section{Introduction} \label{sec:intro} \subsection \subsubsection Text with \cite{hatcher2008} \subsubsection \subsubsection \subsubsection \subsection \subsubsection \subsubsection \subsubsection \bibliographystyle{plain} \bibliography{bibfile} \end{document} –  Keith Oct 22 '12 at 6:34
You can edit your own questions to add something or correct it. So you don't have to squeeze your working code into a comment without formatting. –  Benedikt Bauer Oct 22 '12 at 6:37
@Keith - I've taken the liberty of stripping down your MWE to something that really focuses on the situation at hand. Please try to compile it (LaTeX, BibTeX, LaTeX, LaTeX) and see if the problem persists. If the problem persists, check if there's an entry named hatcher2008 in your bib file. Also, note that \section and \subsection commands take a mandatory argument; your full MWE has little chance of compiling properly. –  Mico Oct 22 '12 at 6:44
There should be no closing brace after the key, only a comma: @article{hatcher2008curcumin, title=.... Also bibtex generates a log-file (with the ending .blg), check it for error messages. –  Ulrike Fischer Oct 22 '12 at 9:23