2D tutorial error

i am studying the tutorial "Making an “Angry Birds” style game - Part 1 " on unity website. My unity is 5.3.0.
Cound you help me why there is a error?Thank you so much!!


@Nickymouse: What error do you get? What is “spring”? Did you defined everything? Since I didn’t go through this tutorial myself I can only try to help you…

private bool clickedOn;

void OnMouseDown () {
if (Input.GetMouseButtonDown (0)) {
spring.enabled = false;
clickedOn = true;