Mobile input (705848)

How can I change it to work for mobile devices?

using UnityEngine;


public class CameraController : MonoBehaviour {

    public float panSpeed = 30f;
    public float panBorderThickness = 10f;

    public float scrollSpeed = 5f;
    public float minY = 10f;
    public float maxY = 80f;

    // Update is called once per frame
    void Update () {

        if (GameManager.GameIsOver)
        {
            this.enabled = false;
            return;
        }

        if (Input.GetKey("w") || Input.mousePosition.y >= Screen.height - panBorderThickness)
        {
            transform.Translate(Vector3.forward * panSpeed * Time.deltaTime, Space.World);
        }
        if (Input.GetKey("s") || Input.mousePosition.y <= panBorderThickness)
        {
            transform.Translate(Vector3.back * panSpeed * Time.deltaTime, Space.World);
        }
        if (Input.GetKey("d") || Input.mousePosition.x >= Screen.width - panBorderThickness)
        {
            transform.Translate(Vector3.right * panSpeed * Time.deltaTime, Space.World);
        }
        if (Input.GetKey("a") || Input.mousePosition.x <= panBorderThickness)
        {
            transform.Translate(Vector3.left * panSpeed * Time.deltaTime, Space.World);
        }


    }
}

On mobile devices you can use accelerometer or touch input for that. Take a look at this manual page Unity - Manual: Mobile device input