Preloader for existing fla

Hi guys,

I am developing a website in flash, I need to create a preloader for the file.

I know to create a preloader for importing images for (eg. img.bytesLoaded/img.totalbytes.)

Now I need what would I have to calculate the bytes loaded for the same existing fla file. and how to proceed.

Hope, I have explained clearly, let me know if anyone not get clear.

Please help me

Thanks in advance.