NEED MAJOR HELP! platform game jumping problem

1

I have code (below) that allows the character to move [COLOR=black]so that it alows it to rotate to the ground, but now I’am try to make him jump but it does not seem to work, if you could please help adjust the code so that the character can jump, it would be alot of help[/COLOR]

onClipEvent (load) {
this.dir = 1;
function updateBB ()
{
while (!_root.ground.hitTest (_root.bb._x, _root.bb._y, true))
{
_root.bb._y++;
}
while (_root.ground.hitTest (_root.bb._x, _root.bb._y, true))
{
_root.bb._y–;
}
}
}
onClipEvent (enterFrame) {
if (Key.isDown (Key.RIGHT))
{
this._x += 10;
this.dir = 1;
}
if (Key.isDown (Key.LEFT))
{
this._x -= 10;
this.dir = -1;
}
while (!_root.ground.hitTest (this._x, this._y, true))
{
this._y += 5;
}
while (_root.ground.hitTest (this._x, this._y, true))
{
this._y–;
}
//see A
//_root.cc._y = this._y;
_root.bb._x = this._x + (20 * this.dir);
_root.bb._y = this._y;
updateBB ();
rot1 = Math.atan2 (_root.bb._y - this._y, _root.bb._x - this._x);
this._rotation = rot1 * 180 / Math.PI;
if (this.dir == -1)
{
this._rotation += 180;
}
this._xscale = this.dir * Math.abs (this._xscale);
updateBB ();
}