UNITY Camera Controller

using System.Collections;
using System.Collections.Generic;
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;


    // Use this for initialization
void Update(){

 if (Input.GetKey("w") || Input.mousePosition.y >= Screen.height - panBorderThickness){
     transform.Translate(Vector3.forward*panSpeed* Time.deltaTime, Space.Self);
}
if (Input.GetKey("w") && Input.GetKey("left shift")){
     transform.Translate(Vector3.forward*panSpeed*5* Time.deltaTime, Space.Self);
}
 if (Input.GetKey("s") || Input.mousePosition.y <= panBorderThickness){
     transform.Translate(Vector3.back*panSpeed* Time.deltaTime, Space.Self);
}
if (Input.GetKey("s") && Input.GetKey("left shift")){
     transform.Translate(Vector3.back*panSpeed*5* Time.deltaTime, Space.Self);
}
 if (Input.GetKey("d") || Input.mousePosition.x >= Screen.width - panBorderThickness){
     transform.Translate(Vector3.right*panSpeed* Time.deltaTime, Space.Self);
}
if (Input.GetKey("d") && Input.GetKey("left shift")){
     transform.Translate(Vector3.right*panSpeed*5* Time.deltaTime, Space.Self);
}
 if (Input.GetKey("a") || Input.mousePosition.x <= panBorderThickness){
     transform.Translate(Vector3.left*panSpeed* Time.deltaTime, Space.Self);
}
if (Input.GetKey("a") && Input.GetKey("left shift")){
     transform.Translate(Vector3.left*panSpeed*5* Time.deltaTime, Space.Self);
}
 if (Input.GetKey("e")){
     transform.Rotate(Vector3.up*panSpeed*3 * Time.deltaTime, Space.World);
 }
 if (Input.GetKey("q")){
     transform.Rotate(Vector3.down*panSpeed*3 * Time.deltaTime, Space.World);
 }
float scroll = Input.GetAxis("Mouse ScrollWheel");
Vector3 pos = transform.position;
pos.y -= scroll * 1000 * scrollSpeed*Time.deltaTime;
pos.y = Mathf.Clamp(pos.y,minY,maxY);
transform.position = pos;
}
}