How do I set the document body to be Times New Roman and Section headings to be Arial?

Question

Possible Duplicate:
Change section fonts

for a University Assignment I have been given some 'House Style' rules which must be adhered for all the documentation. These are:

Main Text Body: Times New Roman, 12pt

Heading 1: Arial, 16pt

Heading 2: Arial, 14pt

Heading 3: Arial, 12pt

I know that I need to use XeLaTeX in order to use system fonts, however, no matter what I try, I cannot get the document to display correctly.

Any idea on how I would implement this is Tex?

Answer 1

Modifying the answer here to the sizes you need, this should be quite straightforward:

% Compile with XeLaTeX or LuaLaTeX
\documentclass[12pt]{article}
\usepackage[tmargin=1in,bmargin=1in,lmargin=1.25in,rmargin=1.25in]{geometry}
\usepackage{fontspec}
\usepackage{xcolor}
\usepackage{titlesec}
\defaultfontfeatures{Ligatures=TeX}
% Set sans serif font to Arial
\setsansfont{Arial}
% Set serifed font to Times New Roman
\setmainfont{Times New Roman}
% Set formats for each heading level
\titleformat*{\section}{\fontsize{16}{18}\bfseries\sffamily}
\titleformat*{\subsection}{\fontsize{14}{16}\bfseries\sffamily}
\titleformat*{\subsubsection}{\fontsize{12}{14}\bfseries\sffamily}

\begin{document}
\section{A section}
This is some text.
\subsection{A subsection}
\subsubsection{A subsubsection}
\end{document}