Calling a mouse event handler without the event

I am writing a program that needs to go to a random frame after clicking a button. However, the program also needs to start on a random frame. When I call the function at the start of the program it gives me an 1120: Access of undefined property event error. The function is originally written as followed:

function randomMatchedTrial(event:MouseEvent) {
… lots of code that probably doesnt matter, but let me know if it does…
}

the program starts by calling the function as followed:

randomMatchedTrial(event)

Can event handler functions be called outside of the event listeners they are handling?