text browser game

I'm pretty noobish at web coding / webdev.  I'm trying to figure out how I could write a browser game using only JavaScript on the client-side (ie. no browser plug-ins).  But I'm stuck on figuring out how to handle everything server-side.

The only thing I've thought of is to store everything in a SQL database, and just have the AJAX post some information to a PHP file that will take care of everything.  However, I'm wondering if there are other, better ways of doing this that I can't think of.  I'm also not sure about handling concurrent players because I haven't done very much with databases before, so I'm not sure whether I'll have to worry about race conditions or something.

Any ideas or advice would be appreciated.

SQL [...] AJAX [...] PHP
You do not need any of those things. Data can be stored in any format, not just in an SQL database; AJAX is not necessary if you do things correctly; any scripting language can be used (not just a bastardised macro language). Consider a javascript platform game:

- The entire thing could be one (let's say Perl) script that generates the page, including (dynamically) all <script ... /> tags necessary
- Global / engine code can be kept in static .js files.
- Level data can be kept in plain text files, or however you need. They could perhaps be parsed to generate javascript containing global variables, like tiledata
- Per-user persistent data can be kept in the same way, and accessed with GET parameters or something.
- Levels are specified in GET also.
- On completion of a level, a simple hypertext link appears (through javascript) that simply links to "game.cgi?level=" + (level + 1)

It's not difficult to avoid using ENTERPRISE stuff like AJAX when you don't need to.