Whats the reason of document.selection?

[drcolossus]

Hi all,
I want to write a jsfl script where I can import a ton of bitmaps onto the stage, then do a selectAll, create an array of the selection by using document.selection and then convert bitmap by bitmap to a symbol in the library.
This however seems not to be possible because senselessly ConvertToSymbol cannot be used with the selection array.
Is there any usage actually for document.selection? And if somebody has an idea how to still perform my described action, it would be very cool to know.

Thanks!