character is bouncing when hits the ground. it does not stay stable - actionscript-3

Question

The question is clear. Character is stable on the stage and background and ground is moving. But when character hits the ground, it bounces again and again. Here is the code. how can i solve it? When i move the character its working perfect but when the moving object is ground bouncing problem happens.
here is the problem : http://www.swfcabin.com/open/1391814250
public function controller():void
{
if (rightKey || leftKey || jumpKey)
{
if (rightKey)
{
if (jumpWalk || canJump)
{
hero.gotoAndStop(2);
hero.scaleX = 1;
xSpeed -= speed;
}
}
if (leftKey)
{
if (jumpWalk || canJump)
{
hero.gotoAndStop(2);
hero.scaleX = -1;
xSpeed += speed;
}
}
if (jumpKey && canJump)
{
ySpeed += 15;
canJump = false;
}
}
else
{
hero.gotoAndStop(1);
}
if(!canJump){
hero.gotoAndStop(3);
}
ySpeed -= gravity;
if(ySpeed >10){
ySpeed = 10;
}
else if(ySpeed < -10){
ySpeed = -10;
}
if(xSpeed>10){
xSpeed = 10
}
else if(xSpeed < -10){
xSpeed = -10;
}
xSpeed *= 0.8;
level.x += xSpeed;
level.y += ySpeed;
}// controller function
public function loop(event:Event):void
{
controller();
while(level.hitTestPoint(hero.x , hero.y + hero.height/2 -1 - ySpeed , true)){
trace(ySpeed +"dasd");
ySpeed ++;
canJump = true;
} }

Answer 1

Here is what is happening now: when you are embedded in terrain, you are increasing the ySpeed -- the upward momentum -- until one 'tick' pulls the character out of the ground. But then the character is flying upward, because you increased their upward momentum. They still have that upward momentum until gravity pulls them back down, so they will keep 'bouncing'. To fix this, do the following:
Instead of ySpeed ++; in the main loop, try level.y++; This would represent pulling the hero out of the terrain when he is embedded (or actually pulling the terrain down, since your character is stationary), instead of changing his momentum to get him out.
You should also add ySpeed = 0; in there. That would represent losing all of your y-momentum when you hit the ground.
So your main loop would look like this:
public function loop(event:Event):void
{
controller();
while(level.hitTestPoint(hero.x , hero.y + hero.height/2 -1 - ySpeed , true)){
trace(ySpeed +"dasd");
level.y++;
ySpeed = 0;
canJump = true;
} }