How to create a polygon in runtime?

Hi all,I want to create a polygon in runtime,not in editor window. All points are given。
Look this code, it doesn't work ,where is the mistake? Thank you!

Code (CSharp):

1. Polygon.points[0] = Vector3.zero;
2.  
3.             Polygon.points[1] = new Vector3(1, 0, 0);
4.  
5.             Polygon.points[2] = new Vector3(1, 0, 1);
6.  
7.             Polygon.points[3] = new Vector3(1, 0, 2);
8.  
9.             Polygon.points[4] = new Vector3(0, 0, 1);
10.  
11.             Polygon.mesh.ToMesh();
12.             Polygon.mesh.Refresh();