cs0131 error !!

hello everybody
i’m trying to learn unity and i faced this problem :

**using UnityEngine;
using System.Collections;
[RequireComponent (typeof(BoxCollider2D))]
public class Controller2D : MonoBehaviour {

BoxCollider2D collider;
void start (){
	Collider = GetComponent<BoxCollider2D> ();


and this is the code of the problem :
Assest/Scripts/Controller2D.cs (10,17) error CS0131: The left-hand side of an assignment must be a variable, a property or an indexer

anyone can hlp me and told me where is the problem to not make it in the futur plz

in future, try to format ALL of your code - the line number from the error message states where the problem is but because of the incorrect formatting, it’s no as easy to find.

in this case though, your problem is somewhat obvious. this line:

Collider = GetComponent<BoxCollider2D> ();

should read:

collider = GetComponent<BoxCollider2D>();

everything in the code is case sensitve.