huanix

I knew it was possible to create a dynamic dependent drop down form using PHP, MySQL, and JavaScript, but I had never had an excuse to use one before my Christmas-break project. I have always thought the forms were neat - like when you select a Country and the next drop-down automagically displays the states from that country. These are also referred to as drill down menus.
It’s “family time”, so I’m building a basic inventory control system for the school I work at, and one of the basic goals is that users would select their “hardware type” (tv, pc computer, mac computer, laptop, etc.) and subsequently select the model # from a list rather than entering it manually. In addition, an administrator has the option to add both hardware types and models to the list at his/her discretion.

All of these things require a dynamic dependent drop down list. I found several resources for completing this task, and after several hours of work, I got it to work using what I believe is the simplest method. You may be far more skilled than I am, and this may be a breeze for you, but I have very little knowledge of JavaScript, so I relied on PHP as much as possible.
Many folks use DreamWeaver to create these menus - I am challenge-oriented, so all of my techniques refer to hand-coded methods.

The first and most highly regarded source for creating dependent dynamic drop downs is the Matt Kruse method , Matt has written an extensive JavaScript library that simplifies the entire dynamic dropdown task.. and it does, but because of my unfamiliarity with JavaScript, I had trouble adding the database through PHP.
I was initially stoked about an AJAX method, and I found one at webmonkey , but I am a novice to AJAX, and I couldn’t make it happen.
I also tried codefixer , but after some struggling, I decided it wasn’t the method for me.

All of this to say, I did eventually find the magic, and it was relatively easy to use (if you add a trick). The source is at wrox , and the trick I used to make it work was to create a simulated database using their structure, and slowly migrate it over to my setup. It worked really well, used a minimum of code, and does the job perfectly!

Here is my cleaned up and working version of the script:http://www.huanix.com/files/dependent_select/dependent_select.php