there is an error... help!!

the error readz

An object reference is required to access non-static member `UnityEngine.Rigidbody2D.velocity’

`using UnityEngine;
using System.Collections;

public class PLAYER_CONTROLLER : MonoBehaviour {

public float moveSpeed;
public float jumpHeight;

// Use this for initialization
void Start () {


// Update is called once per frame
void Update () {
if(Input.GetKeyDown (KeyCode.Space)){
	Rigidbody2D.velocity = new Vector2(0,jumpHeight);


You need to get the Rigidbody2D component of the object you want to jump.

Rigidbody2D rb;

void Start(){
    rb = GetComponent<Rigidbody2D>; // If this script is attached to the object with the Rigidbody2D component, then this is enough.

// Replace the same velocity line of code with the following line. 
rb.velocity = new Vector2(0, jumpHeight);