Jump and falling

1

hi,

I draw a ball and a ground ,gave them instance name “ball” and “ground”
Now I want to make the ball jump up and fall down using (Key UP)as in the most platform games…

I gave the following code to the ball mc
but I know there are some declarations missing…coujld you please fix so that I can jump objects
thanks

onClipEvent(enterFrame)
{
if (Key.isDown(Key.UP))
{
this._y+=5;
}
}