[Plugin: Simple Mathjax] Not work for premble in "Custom LaTeX preamble"

Firstly, I think mathjax is the best Latex render for html, especially in Firefox, it looks perfect. In fact, in my site:https://wamath.sinaapp.com/, I have tried to translate some Latex code to html too, such as \tableofcontents,\section,\subsection,\subsubsection, and define some new environment, such as Theorem(thm), Lemma(lem) and so on, which can auto-numbering it works almost well so far, you can view here for an introduction to the plugin(Latex2Html).

But, there is a problem when I try to set some commend as
\newcommand{\pt}{\partial} and put it into “Custom LaTeX preamble” box, it works for IE9, Firefox8.0, Chrome16.0, however, for IE6, it is not work, and it says that has some problem of the js. I try to solve it, but failed.

In fact, I can define it in the “Custom mathjax config” box, as

Macros: {
pt: '{\\partial}'
}

which will work for all the browser incuding IE6.

So can you check the code, and tell me how to solve it, since a lot of my firends are still use IE6. Thanks!

https://www.ads-software.com/extend/plugins/simple-mathjax/