Playing mc only when jpg loaded

I’m loading jpgs into a mclip called holder.
I need to execute another movieclip called “flash” when the picture is
loaded.
The flash movieclip is a sort of bright so can’t be called to make play when
the
button is pressed since the jpg will start to load… (they must appear
together).

How can I do that?

the “flash” must appear everytime a picture finished it’s loading…

Can someone give me an answer, tutorial or something please?
I’m stuck…

Thank you!