Dynamicly changing image from form components

Hello everybody, I have come here because I can not find any tutorial on what I am trying to do because I am not sure what the technique is called that I need.
Basically, I am designing an e-commerce site, but instead of selling many different products, I am selling one, Shoes. You see, they are customizable, so I only will build one page to customize them that has:
a picture of a blank shoe, a picture of laces, and a picture of a little charm on the laces, with three drop down boxes; color, laces, and charms. Basically I want it so that when you chose a color from the drop down, the picture of the blank shoe changes to that color. Sounds simple, but I do not even know what programming language I can do this with, or how to set it up. Do I need all the possible images it can be, or are there properties I could use like in Flash, where I can change the color property? I imagine this is a very involved job, and I only know a little bit of everything, I am really a designer so I am totally lost here. Can someone please point me in the right direction of what language I could use, or a tutorial, or even what you call this technique?
The thing is, I will be connecting it to a database which will contain the number of shoes left that color, the number of laces, and number of little charms I put on the laces. When someone chooses the shoe they want, and then proceeds to checkout, I need that info sent to me so that I can make the shoe. My host has mySql and PHP so I am wondering if this is an option, and how would I get started? Here is a graphic example of what I mean
So basically, I have drop downs that should
1: change the image to match what is chosen, and
2: send that info to me in an email or into the database, either one.
The best example I have is of a car website, like toyota.com, where you choose your options and color and depending on what you choose, the picture of the car changes. And obviously toyota gets that information so they can build that car for you, but when I look at that source, it seems like javascript code defined somewhere else, so there is no example for me to look through. How can I start this? I have been using this site for years and have never needed to post my own thread because I just read through all of them, but I just cant seem to find info on this topic. If anyone knows what this is called, or has done something similar in the past, please help me out. Thanks so much.