Horizontal Rule Across page

Question

Possible Duplicate:
What is the \rule equivalent for \hrule?

I found this online to produce a horizontal line across the page:

\begin{center}
    \line(1,0){250}
\end{center}

But I want it to stretch across the page with the width of the text. So I tried:

\begin{center}
    \line(2,0){\textwidth}
\end{center}

Although this displayed correctly it threw up a lot of errors that I'd like to remove. The errors were:

 ./Template.tex:28: Missing number, treated as zero.
 <to be read again> 
     \vrule 
 l.28 \line(2,0){\textwidth}                        
 ? 
 ./Template.tex:28: Illegal unit of measure (pt inserted).
 <to be read again> 
     \vrule 
 l.28 \line(2,0){\textwidth}

So how else could I try to display the line with the width of the page?