How do I script 3D runner jump Left, Right, Slide? Please help.

I have this as my script (any tips?)
------I have this as a my error-----
Assets/MoveRoads/MoveRoads.cs(8,17): error CS0246: The type or namespace name `LinkedList' could not be found. Are you missing a using directive or an assembly reference?

using UnityEngine;
using System.Collections;

public class MoveRoads : MonoBehaviour {

public Transform prefab;

private LinkedList items = new List();

private float posY = 0.0f;
private int numberOfRoads = 3;

// Use this for initialization
void Start () {

//Init the sccene with some road-pieces
for(int i=0;i < numberOfRoads;i++) {
Transform road = Instantiate(prefab) as Transform;
road.Translate (0, posY, i * road.localScale.z);
MoveRoads.AddLast(road);
}
}

// Update is called once per frame
void Update () {

Transform firstRoad = roads.First.Value;
Transform lastRoad = roads.Last.Value;

// Create a new road if the first one is not
// in sight anymore and destroy the first one
if(firstRoad.localPosition.z < -5f) {

roads.Remove(firstRoad);
Destroy(firstRoad.gameObject);

Transform newRoad = Instantitate(prefab, new Vector3(0, posY ,
lastRoad.localPosition.z + lastRoad.localScale.z),
Quaternion.identity) as Transform;
roads.Addlast(newRoad);

}

// Move the available roads along the z-axis
foreach(Transform road in roads) {
road.Translate(0,0, -8f * Time.deltaTime);
}

}
}

 

Please read this and edit your post so your code is readable.
Also, LinkedList is in System.Collections.Generic

 

Many thanks jallen your awesome wont forget.