Car Movements Help

[Gunderak]

I am working on a "Car" for Graal Ghetto and so far all I have is the movement.
For my example I have added a block image to show the "Car".
Although the movement is working perfectly the acceleration isn't.
The problem is when accelerating if you turn it stops accelerating.
Here is what I have so far.
I am entrusting that the Graal community will NOT steal this, as I have spent about an hour and a half just getting this much.
2330 Characters long and 87 lines.
Thanks.

PHP Code:

/*
Scripted by Gunderak.
Intended to be used on Graal Ghetto and Graal Ghetto ONLY.
You may however study this and try to learn from it.
*/
//#CLIENTSIDE
function onCreated() {
  //Disables default movement.
  disabledefmovement();
  //Speed variables
  this.speed = "1";
  this.leftrightspeed = "0.13";
  this.movespeed = "0";
  this.acceleration = "0.10";
  //Begins the timeout.
  onTimeout();
}

function GraalControl.onKeyDown(code) {
   //If the Right-arrow key is pressed.
  if (code == 37) {
    //And if the car is moving.
    //This makes car movements seem more realistic.
    if (this.movespeed > 0) {
      //Raises the angle.
      this.dir += this.leftrightspeed;
    }
  }
  //If the left-arrow key is pressed.
  if (code == 39) {
    //And if the car is moving.
    //This makes car movements seem more realistic.
    if (this.movespeed > 0) {
      //Lowers the angle.
      this.dir -= this.leftrightspeed;
    }
  }
  //If the up-arrow key is released.
  if(code == "38"){
  //Start moving the car and begin to accelerate.
  this.moving = 1;
  }
}

function GraalControl.onKeyUp(code){
  //If the up-arrow key is released.
  if(code == 38){
   //Stop moving the car and begin to decelerate.
   this.moving = 0;
  }
}

function onTimeout() {
  //Shows a block image.
  showimg(3, "block.png", player.x, player.y );
  //Changes the blocks rotation to the correct angle.
  findimg(3).rotation = this.dir;
  findimg(3).zoom = 2;
  //If the angle is less than the minimum resets it to zero.
  if (this.dir < "-6.25") {
    this.dir = 0;
  }
  //If the angle is greater than the maximum resets it to zero.
  if (this.dir > "6.25") {
    this.dir = 0;
  }
  //Just some basic Trigonometry.
  //This part has been removed.
  //If you really want to steal this script you will have to
  //figure the sine and cosine out yourself!
  //If the car isnt accelerating slowly decrease speed.
  if (this.moving == 0) {
    this.movespeed -= this.acceleration / 3;
  } else {
    if (this.movespeed < this.speed) {
      this.movespeed += this.acceleration;
    }
  }
  //If your move speed is less than zero for some reason
  //It will set it back to zero.
  if (this.movespeed < 0) {
    this.movespeed = 0;
  }
  //Continues to loop through the timeout.
  settimer(0.05);
} 


Update
Removed the players movement seeming as it isn't necessary.
Also to make it harder for people to steal this script and actually use it.