get position based on screen unity code example

Example 1: unity how to change the text on a button

GameObject.Find("Button Name").GetComponentInChildren<Text>().text = "Button Text";

Example 2: how to use the mouse scroll wheel to move the camera in unity

float scroll = Input.GetAxis ("Mouse ScrollWheel");
    transform.LookAt (target);
    transform.Translate(0, 0, scroll * speed, Space.Self);