Pre-loader Using Flex 4?

is it possible to create a pre-loader using plainly Flex 4? I've see开发者_StackOverflown tutorials on how to make one but each of them requires that I have Flash Professional or Flash Catalyst.

I have absolutely no experience when it comes to implementing pre-loaders as well as making one. So please try to elaborate a little more.

Thanks!

http://help.adobe.com/en_US/flex/using/WS2db454920e96a9e51e63e3d11c0bf69084-7e3c.html#WS2db454920e96a9e51e63e3d11c0bf62d75-7fef

Hope that helps.

Shaun