Hello all, i'm new and looking for some help

Hey there everyone.

I've been messin around with the TGB trial version to get a feel for it before i decide to buy it.
i started working on this tutorial
Basic Platformer Mechanics

i have gotten to the player movement section , i get all the code there and all i can do is jump. so i decided to trudge on and work with it so i added the reset code for the jump function. with even copying and pasting the code straight from the tutorial , nothing seems to work ; other then the little jump.

here is my code :

function playerClass::onLevelLoaded(%this, %scenegraph)
{
$pGuy = %this;

moveMap.bindCmd(keyboard, "left", "playerLeft();", "playerLeftStop();");
moveMap.bindCmd(keyboard, "right", "playerRight();", "playerRightStop();");
moveMap.bindCmd(keyboard, "space", "playerJump();", "");
%this.setCollisionMaxIterations(2);
}
function playerLeft()
{
$pGuy.moveLeft = true;
}

function playerLeftStop()
{
$pGuy.moveLeft = false;
}

function playerRight()
{
$pGuy.moveRight = true;
}

function playerRightStop()
{
$pGuy.moveRight = false;
}

function playerJump()
{
if(!$pGuy.airborne)
{
$pGuy.setLinearVelocityY(-225);
$pGuy.airborne = true;
}
}
function playerClass::updateHorizontal(%this)
{
if(%this.moveLeft)
{
%this.setLinearVelocityX(-60);
}

if(%this.moveRight)
{
%this.setLinearVelocityX(60);
}

if(!%this.moveLeft && !%this.moveRight)
{
%this.setLinearVelocityX(0);
}
}
function playerClass::updateVertical(%this)
{
%yVelocity = %this.getLinearVelocityY();

if(%this.airborne)
{
%this.setLinearVelocityY(0);
%collision = %this.castCollision(0.005);

if(%collision !$= "")
%this.setLinearVelocityX(0);
}

%this.setLinearVelocityY(100);
%collision = %this.castCollision(0.005);

if(%collision $= "")
{
%this.airborne = true;
%this.setConstantForceY(100);
}
else if(%yVelocity < 0 && %this.airborne)
{
%this.setConstantForceY(100);
}
else
{
%this.airborne = false;
%this.setConstantForceY(0);
}

%this.setLinearVelocityY(%yVelocity);
}

function playerClass::updateMovement(%this)
{
%this.updateHorizontal();
%this.updateVertical();
}
function PlatformerSceneGraph::onUpdateScene()
{
if (isObject($pGuy))
$pGuy.updateMovement();
}


i'm at a complete loss, i want to buy this programs to start plotting out my game ideas, but if i cant get it to work...i'm not sure what else to do.

any help would be great!

thanks a million

~Alex.