convert type `UnityEngine.Ray' to `Ray'

I was thinking of making a mouse cursor. So i use a ray for this, then the point where the mouse hit plane will make a vector between it and the object to rotate it. Well Everything was clear on the paper, but coming on the code, the first line made trouble:

public class Ray : MonoBehaviour {

	void Update() {
		Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

when i’ve coded this unity said: Assets/C#scripts/Ray.cs(6,31): error CS0029: Cannot implicitly convert type UnityEngine.Ray' to Ray’, the fact is… all tutorials say to do this so… what’s wrong?! If someone can help me…

Are you intentionally trying to override the UnityEngine “Ray” class"? Change “…class Ray…” to “…class MyRayClass…”