I have this flash .fla file that me and a couple of friends have been working on, I need to do 2 things with it but do not know how.

The flash project we are working on is a flash project that deals with projectile motion. We are flinging a pumpkin from a slingshot and it flys through the air and hits a teacher from our school

Anyways, we have the code set, we need it to shoot the pumpkin on the press of a button, and we also need it to stop repeatting heh....Like, it has a feild to insert a angle in degrees and an initial velocity and a number of seconds between calculations and it keeps showing the pumpkin fly through the air over and over again hehe....
I do not understand how to make it go only once and on the press of a button... Can someone please help