Scripted plane not showing up

I need to generate a procedural mesh for my project so i first tried to simply script a plane. The problem is that the plane is not visible in the game or the scene view. Please help me figure out what I did wrong.
Here is the script in C#

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class PlaneCreation : MonoBehaviour {
5.  
6.     // Use this for initialization
7.     void Start () {
8.  
9.  
10.     MeshFilter mf = GetComponent<MeshFilter>();
11.     Mesh mesh = new Mesh();
12.     mf.mesh = mesh;
13.  
14.  
15.  
16.         Vector3[] wv = new Vector3[4];
17.  
18.         wv[0] = new Vector3(-2,0,0);
19.         wv[1] = new Vector3(-2,4,0);
20.         wv[2] = new Vector3(2,0,0);
21.         wv[3] = new Vector3(2,4,0);
22.  
23.         mesh.vertices = wv;
24.  
25.  
26.         int[] tri = new int[6];
27.  
28.         tri[0] = 0;
29.         tri[0] = 1;
30.         tri[0] = 2;
31.  
32.         tri[0] = 1;
33.         tri[0] = 3;
34.         tri[0] = 2;
35.  
36.         mesh.triangles = tri;
37.  
38.  
39.         Vector3[] normals = new Vector3[4];
40.  
41.         normals[0] = -Vector3.forward;
42.         normals[1] = -Vector3.forward;
43.         normals[2] = -Vector3.forward;
44.         normals[3] = -Vector3.forward;
45.  
46.         mesh.normals = normals;
47.  
48.  
49.         Vector2[] uv = new Vector2[4];
50.  
51.         uv[0] = new Vector2(0,0);
52.         uv[0] = new Vector2(1,0);
53.         uv[0] = new Vector2(0,1);
54.         uv[0] = new Vector2(1,1);
55.  
56.         mesh.uv = uv;
57.  
58.     }
59.    
60.     // Update is called once per frame
61.     void Update () {
62.    
63.     }
64. }
65.  

Thanks in advance for the help.

 

Can you see it in the hierarchy ? (does the object exist). If it exit, try to flip it : plane are visible in only one side

 

Well I created an empty Object and added the Script, a Mesh Renderer and a Mesh Filter to it. If that is what you mean I so See it in the hierarchy.
I already tried switching the normals but it didn't help.
Maybe I am doing something wrong with the empty Game Object?