turning on and off gravity help

Questions & Answers
1

am doing my first game where my player has to move in x and y directions according to the inputs given from keyboards and has to fall down if there is no inputs are give (i.e) if no keys are pressed.

is there a way to turn on gravity when there are no inputs and turn off if any keys are pressed.

previously i was doing gravity manually. the i used previously is below

using UnityEngine;
using System.Collections;

public class player_script_2 : MonoBehaviour {
	
	Vector3 move;
	float accleration = 10;

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
		
	   move.y = Input.GetAxis ("Vertical");
       move.x = Input.GetAxis("Horizontal");
 
       //Check if no buttons are pressed
       if(Input.GetAxis("Vertical") == 0f && Input.GetAxis("Horizontal") == 0f) {
         if(transform.position.y >= -4.45f) {
          move.y -= 2f;   
         }
       }
        
		print ("before "+ move);
        move.Normalize();
		print ("after "+ move);
 
        float xdir = move.x * accleration * Time.deltaTime;
        float ydir = move.y * accleration * Time.deltaTime;
 
        transform.position = new Vector3(transform.position.x + xdir, transform.position.y + ydir, transform.position.z);
    }
}

sadly according to my script, the player’s jumping or standing on a higher level wont happen as i have given a check for y position.
need help…

2

// Update is called once per frame
void Update () {
move.y -= 2f;
move.y = Input.GetAxis (“Vertical”);
move.x = Input.GetAxis(“Horizontal”);
//Check if no buttons are pressed ** not required **

       }