if(player.hitTestObject(Things Flying Past You))
{
gotoAndStop(Frame Number Here);
}
hitTestObject checks whether or not two objects are overlapping each other. If so this if statement just goes to the frame number you plug in. I assume you have multiple objects flying at you, so in that case you would need to throw a for loop around that if statement to cycle through all of the objects. Depending what class you are calling this from you may have to do this.
(parent as Document).gotoAndStop(Frame);
Assuming the Document class is the main class linked to your flash project.
I hope this helped.