[metapost] An error message when use mptopdf: Undefined control sequence. \documentclass {article}.

[Hongyi Zhao]

Hi all,

I use the metapost shipped with texlive 2007.  When I use mptopdf to
generate pdf figs, tho I can get the right pdf files ultimately, I
will also be given error messages like this:

==============
! Undefined control sequence.
l.44 \documentclass
                   {article}
?
=============

Then I use the entered *x* after the quotation mark *?*, and I will
get the ultimate pdf files.

The attached is my sample file, and the following is my commands to
manipulate the sample file:

=========
hongyi at debian-testing-hy: mpost -tex=latex zScaled.mp
hongyi at debian-testing-hy: mptopdf zScaled.mp
=========

Who can tell me the reason?  What should I do to solve the problem?

Thanks in advance!
---
Hongyi Zhao (赵弘毅)
GnuPG DSA: 0xD108493B

老子道德经：第四十二章
人之所恶，唯孤、寡、不谷，而王公以为称。
故物或损之而益，或益之而损。
人之所教，我亦教之：“强梁者不得其死。”
吾将以为教父。
-------------- next part --------------
A non-text attachment was scrubbed...
Name: zScaled.mp.bz2
Type: application/octet-stream
Size: 1245 bytes
Desc: not available
Url : http://tug.org/pipermail/metapost/attachments/20070225/0d3c6c0f/attachment.obj