Question: I wrote a PHP shell script which include queuing jobs in centOS with 'at' command.
The queue jobs may vary in time and contents which means the system need to keep quite a large number of jobs.
The application logic will also be a bit difficult to setup with cronjob.
Is there a limit in number of queue jobs in centOS or is there any alternative way of queuing jobs?

Answer: 
I really like this article:
[A re-introduction to JavaScript](https://developer.mozilla.org/en/A_re-introduction_to_JavaScript)
First off, start using JSLint on all your code, for at least a week (<http://www.jslint.com>). I'm not going to say you should use it constantly, forever and ever, and it's perfect, because it's not. But, it will help you learn *a lot* about JavaScript, if you take the time to read what it says, and understand why. Even if you disagree, which you may, understand the reasoning behind each message. Then you can decide if it's a tool you'd like to continue using.

The other first step is to pick up a copy of *JavaScript: The Good Parts*. This is by far the best book on JavaScript. It's short, very easy to read, and really will help you learn better JavaScript. <http://oreilly.com/catalog/9780596517748>

Other than that, there are a lot of good blogs to follow. You can find these via google, but I'd look at *Perfection Kills* and John Resig's blog, in particular. I think mine is pretty good too, you can find it via my profile if you're interested :)