How do i make up and down button script for Mobile in Unity 5.3.2

Im making a 2d game that only moves up and down for Android but cant seem to find a script for simple up and down button movement. i watched tons if tutorials on how to move with mobile but none explain how to move Up and Down. i have a script that works perfectly fine on my computer but i want to convert the script for touch screen movement for my android device.

using System.Collections;

public class PlayerMovement : MonoBehaviour { public enum type {platformer, topdown}; public type moveType; public float moveSpeed, jumpHight;

 // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void Update () 
 {

     if (moveType == type.topdown && Input.GetAxisRaw("Vertical") > 0)
     {
         transform.Translate (Vector2.up * Time.deltaTime * moveSpeed);
     }
     else if (moveType == type.topdown && Input.GetAxisRaw("Vertical") < 0)
     {
         transform.Translate (Vector2.down * Time.deltaTime * moveSpeed);
     }
 }
     

}