How to make Full Screen at different pc

i wanted the game when builded, its able to make/set to full screen at different pc, as different pc have different resolution.so how am i suppose to do?

i got builded 1,under the gaphics

Screen resolution: got those>

640x480
720x480
720x576
800x600
1024x768
1152x864
1280x720
1280x768
1280x800
1280x1024
1360x768
1440x900

But all is too small and cannot full screen

You can just put Screen.fullScreen = true somewhere in your code, maybe connected to a button called “Full Screen” or something. If you want to toggle just use the old Screen.fullScreen = !Screen.fullScreen.

It will set the game to full screen on whatever machine it runs.

when set to biggest resolution, starting the unity is fullscreen and awhile when come to my game its not full screen

my scrip funtion Start is below

function Start () {

//MainCamera.
Screen.SetResolution (1280,800,false);

Why No matter how i choose the resolution 640x480 720x480 720x576 800x600 1024x768 1152x864 1280x720 1280x768 1280x800 1280x1024 1360x768 1440x900 or check or didnt check the Window mode

My game will come to a fix resolution of 1280x800

So why cant be Full Screen ^^

function Start () {

// camera2 = GameObject.Find(“User”).GetComponent(UserScript);

//MainCamera.
Screen.SetResolution (1280,800,false);
userSwitch = 1; 

//Camera
mainView2 = GameObject.Find("MainCamera2");
mainViewCam2 = mainView2.GetComponent(Camera);
mainView = GameObject.Find("Camera");
mainViewCam = mainView.GetComponent(Camera);

mainViewCam2.enabled = false;

//Waypoints
GameObject.Find("Home").renderer.enabled = false;
GameObject.Find("p1").renderer.enabled = false;
GameObject.Find("p2").renderer.enabled = false;
GameObject.Find("p3").renderer.enabled = false;
GameObject.Find("p4").renderer.enabled = false;
GameObject.Find("p5").renderer.enabled = false;
GameObject.Find("p6").renderer.enabled = false;
GameObject.Find("p7").renderer.enabled = false;
GameObject.Find("p8").renderer.enabled = false;
GameObject.Find("p9").renderer.enabled = false;
GameObject.Find("p10").renderer.enabled = false;

//
// //Line

// pathPoints = new Vector3[maxPoints];

// pathLine = new VectorLine(“Path”, pathPoints, lineMaterial, 12.0,

LineType.Continuous);

homePos = GameObject.Find("Home").transform.localPosition;

// Debug.Log (homePos);

homePos.x = ( homePos.x + 3285.686 ) * (570-20) / (824.0381 + 3285.686) + 20;

homePos.z = ( homePos.z + 1327.897 ) * (780-150) / (3300.656 + 1327.897) + 150;

points1.push(Vector2(homePos.x, homePos.z));

points2.push(Vector2(homePos.x, homePos.z));

// Debug.Log(points1 + “,” + points2);

}
this is under start my script too long le lol dunno what part to be post in ,think i just post this first if not,then i will post another 1