Sub-figures using subfloat in LaTeX

subfloat.tex

% Package for subfloat
\usepackage{subfig}

% Figure with two sub-figures
\begin{figure}
\centering
\subfloat[]
{
    \includegraphics[scale=.5]{fig-1.pdf}
    \label{fig:foo-1}
}
\subfloat[]
{
    \includegraphics[scale=.5]{fig-2.pdf}
    \label{fig:foo-2}
}
\caption{ Two foo figures. }
\label{fig:foo}
\end{figure}

Can you please tell how to control captions of subfigures?