Moving Platform Error

Hey i have this script which is meant to make a platform simply move between two designated points.

public class SimpleLerper : MonoBehaviour
{
public Transform pointOne;
public Transform pointTwo;
public float moveTime = 3.0f;
private float startTime;

void Awake()
{
        this.enabled = false;
}

void Start()
{
        startTime = Time.time;
}

void Update()
{                            
        float fracTime = (Time.time - startTime ) / moveTime;

        // Debug.Log("Frac time: " + fracTime);

        transform.position = Vector3.Lerp(pointOne.position, pointTwo.position, fracTime); 

        // reached destination point
        if(fracTime >= 1.0f)
        {
                startTime = Time.time;          // reset start time

                // switch points around
                Transform temp = pointOne;
                pointOne = pointTwo;
                pointTwo = temp;
        }                       
}

}

However i am getting error: error CS0246: The type or namespace name monobehaviour could not be found. Are you missing a using directive or an assembly reference?

Thanks

However i am getting error: error
CS0246: The type or namespace name
monobehaviour could not be found.

using UnityEngine;

Do you have this in the beginning of your script?