How to fill a circle image by every second

Hi! I came back with a project for fun but i need help. Every time i press build is showing to me this error:

** NullReferenceException: Object reference not set to an instance of an object
AceDeCeas.Update () (at Assets/Scripts/AceDeCeas.cs:23)

Here you have my source

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class AceDeCeas : MonoBehaviour {

float time=0;
public Image secundar;
public Image minutar;
public Image orar;
public Slider slider1;
void Start () {
	secundar = GetComponent<Image> ();
	minutar= GetComponent<Image> ();
	orar = GetComponent<Image> ();
	slider1 = GetComponent<Slider> ();
	secundar.fillAmount = 0;
}

// Update is called once per frame
void Update ()
{time += Time.deltaTime;
	secundar.fillAmount = Mathf.Clamp (time, 0, 1);
}

}

First I wanted to make something to work with a slider but still error was showing.

I’ll really appreciate the help :slight_smile:

Serju

As @El_Nacho said in comm I need to attach the script at component. Thank you man :slight_smile: