Platform game - disable jump when falling

Question

Hello everyone,
I'm making a platform game in AS3. I've sorted the left,
right and jumping movement of my character - apart from one jumping
problem:
When the up arrow key is down it sets the jump var to true.
ENTER_FRAME function detects when jump = true and it decreases the
characters y position by the var velocity while at the same time
decreasing velocity by 1.5px. So my character jumps up to a certain
height then comes down - great! There is a hit test to stop the
jump/fall.
BUT when the character falls off a platform he can still jump
when the up arrow is pressed. I've been racking my brains but I can
stop the character from jumping if its falling.
Code aqttached.
Any help would be MUCH appreciated.
Thanks,
Ryan

Answer 1

on ENTER_FRAME the velocity var is decreasing while the jump
var is true. This is true when the up arrow as been pressed and
isn't false until the character hits the ground. Therefore pressing
the up arrow again while in the air (from a jump) dose not effect
anything.
You second answer is closer to the solution, I've tried this
approach before, but it badly effects the jump.
This 'else' part of the code controls the character to fall
if not hitting the ground:
stage.addEventListener(Event.ENTER_FRAME, hitCheck);
function hitCheck(event:Event):void
if (ball_mc.hitTestObject(ground_mc))
jump = false;
velocity = 35;
else
ball_mc.y += 16;
If I cancel the jump function in the else then as soon as the
char starts the jump and is not hitting the ground it will fall
back to the ground. I hope that makes sense?
Thanks,
Ryan
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