There should have been a CD that came with the camera that has the Operating instructions on the CD.
You can download the operating instructions here:
Click "view" to the right of the first line that says "Operating Instructions".
Then put a check mark in the box called "I Accept".
Then click the "view" to the right.
I can't find the answer to your question about the flash.
But I doubt that you can, when using the IA button.