MySQL 5 in MySQL 4 compatible mode for one database?

In a recent project, I have to maintain some PHP code. I set up a development server and installed MySQL, Apache, PHP, ..etc.

The program is terminated with an error:

• Unknown column _ _ _ in 'on clause' Cannot select ....

Google shows that it's a change of syntax around JOINs, parentheses are needed.

As you may imagine, fixing all that PHP SQL strings will be the last resort. >_<

Is is possible to config MySQL 5 to run at MySQL 4 compatible mode?

Or even better, for only one database? Thanks!

p.s. Since we are going to host the code on a new production server (MySQL 5 on a CentOS box), the chance to install MySQL 4 on the new server might be slim.

Would it be possible to run 2 versions of mysql on the server in question?

http://dev.mysql.com/doc/refman/5.0/en/multiple-servers.html

version 4 for this projects and version 5 for everything else.