Script Help Please

I am using this script to replay a function when a button is pressed

function replay() {
delete this.onEnterFrame;
row = -1;
pixelSize = 1;
this.onEnterFrame = fill;
}

How would I go about changing that to operate as soon as the page loads instead of having to push the button…keeping in mind that onClipEvent (enterFrame) won’t work because it has to be assigned to a movie clip instance.