How to setup camera to show full screen...?

I am a new in unity. I want to make a 2D game but I don’t know how to setup camera that showing just a background image(plane with texture) in full screan when you playing a game? For example a hidden object game have a scene that is static don’t have a movement and scene is fitted to the screen when you playing game.

Try this script:
you have to attach a gui texture component and name the script “FullScreen”, put the texture you want to display in the gui texture

using UnityEngine;
using System.Collections;

public class FullScreen : MonoBehaviour 
{
	void Start () 
	{
		float ScreenWidth = Screen.width;
		float ScreenHeight = Screen.height;
		float PixelInsetX = (Screen.width / 2) * -1;
		float PixelInsetY = (Screen.height / 2) * -1;
		guiTexture.pixelInset = new Rect(PixelInsetX, PixelInsetY, ScreenWidth, ScreenHeight);
	}		
}

Thanks very much… Works great…

guiTexture is obsolete