PreLoader ... What's the Use ...
Normally the very last thing to do is create your preloader so everything runs smooth ... but since it's the very first start of your new site ... let's start with it and get some things done ... and understand a little bit better how Flash actually works.
Why a preloader ?
The idea of a preloader is not so much as to show how bandwith consuming you are and how heavy flash movies can be but to make sure that everything you made actually runs very smooth and no waiting time occurs after you optimized everything to the best of your abilities ...
In the first part we discovered all the different possibilities of Flash and some naming things ... now get it straight a little.
When you start on your Flash Site you designed the concepts and created a structure.
For a starter we will start with one movie (although our goal is to achive a complete site so we will end up with a lot more than one movie but that's for later)
You opened a new Flash Movie and created some scenes to make sure it looked nice and structural ...
You start with one empty Scene (called scene1) and you add the layers we discussed in Flash001 to this scene ...
Start with it before you do anything else ... so add // code // buttons // main // background as a start.
Next you fire up your scene panels Window > panels > scene and hit the duplicate scene button a few times. (it's the first down under) and rename the scenes accordingly.
Scene names would be PreLoader, Intro, Main, CopyRight, ... and all other possibilities.
Pay attention to the order you gave them ... since the actual swf you will present to your user is just one single big timeline going from A to Z and thus downloading everything from the beginning towards the end.
So after you did this you are ready to build your complete site // presentation and you just didn't touch the very first preloader scene yet ... and now the preloader comes into play ... but first
If you already have a little Flash Movie you want to try this one on do read the next part // if you don't well this will learn you a few other tricks 
Select a few beautiful babes, pictures of your kids or wildlife photographs on your harddrive and we will import these into Flash (please note that it's to explain the purpose of a preloader, be very strict on using Bitmapped Images in Flash and try to keep them as small as possible, because this is not the concept of Flash)
Goto Insert > New Symbol ( Ctrl + F8) and give it a name like MyUBB1.
Goto File > Import and select the picture you want to import.
Click OK
You see the image on stage with a grey frame around it (it's selected, otherwise click on it).
Save your work !!! CTRL + S
Now a little trick ...
Goto Modify > Trace Bitmap
Select the Color TresHold and Minimum Area // Be Carefull here cause if the values are to low it will eat your CPU and your system may freeze.
Play it a little around with different settings untill you get the feeling.
What we just did was traced the bitmap into a vector and if done wizely we changed the size downwards (if you want the real image look don't use this option, because the file size will be bigger)
Click outside the image and than click on certain parts.
You see you can alter the vectors now ...
Hit CTRL + A (select all) and go to Modify > Optimize
Select Maximum and see how much percentage you gain ...
It's all in the mathematics ...
Every Bitmap or image you create you should optimize as much as possible ... to get the best performance ...
So back to our preloader stuff ...
Go to the scene and you see it's empty.
Drag on scene MAIN your created artwork. You see you have two in your Library (the original picture and the optimized vector one).
Drag the optimized one on scene Main and the Bitmapped one on Scene Main2.
If you feel like repeat the complete process a few times with different pictures. (save your work once in a while, since Flash has no auto save function)
Go Into the Publish Settings (File > Publish Settings) and activate Generate size Report on the Flash Tab.
Click OK
Hit F12 to preview the swf
See how fast it goes on your local PC ...
Open the trace report and look at the figures (it's published as a TXT file in the same directory where you saved the FLA)
Now go back to Flash and hit CTRL + ENTER ( Control > Test Movie )
Goto View >Show Streaming (again CTRL + ENTER)
You see the graph and you see how it would look at someone with a 28.8 connection ... (you can set connections in the DEBUG screen) .... YEEZ GOT SCARED ???
Well ... that's one of the reasons why a preloader can help you ... but first of all you need to optimize and test the movie as far as possible before you start building a preloader ....
So ... now you discovered the pitfalls it might be a good idea to go back and do some optimizing and make a new analyze ...
You see it's not all that fun ... but when you finally have a good tuned movie than we can put the things that needs in a preloader in a preloader ... but First and For All ... make sure you don't really need a preloader ... that's the power of Flash !
I will add a second on PreLoaders later ...
Greetz
Knuff
