Condition on Character Movement

I copied and pasted the character movement script from one of the Unity sample projects. The code is below. How do I make it so this movement only occurs when the player is holding down a key/button?

Thank you.

using UnityEngine;

public class Char1MovementAlt : MonoBehaviour
{
public float speed = 6f;            // The speed that the player will move at.

Vector3 movement;                   // The vector to store the direction of the player's movement.
Animator anim;                      // Reference to the animator component.
Rigidbody playerRigidbody;          // Reference to the player's rigidbody.
int floorMask;                      // A layer mask so that a ray can be cast just at gameobjects on the floor layer.
float camRayLength = 100f;          // The length of the ray from the camera into the scene.

void Awake ()
{
	// Create a layer mask for the floor layer.
	floorMask = LayerMask.GetMask ("Floor");
	
	// Set up references.
	anim = GetComponent <Animator> ();
	playerRigidbody = GetComponent <Rigidbody> ();
}


void FixedUpdate ()
{
	// Store the input axes.
	float h = Input.GetAxisRaw ("Horizontal");
	float v = Input.GetAxisRaw ("Vertical");
	
	// Move the player around the scene.
	Move (h, v);
}

void Move (float h, float v)
{
	// Set the movement vector based on the axis input.
	movement.Set (h, 0f, v);
	
	// Normalise the movement vector and make it proportional to the speed per second.
	movement = movement.normalized * speed * Time.deltaTime;
	
	// Move the player to it's current position plus the movement.
	playerRigidbody.MovePosition (transform.position + movement);
}
}

void FixedUpdate()
{
if (Input.GetKey(KeyCode.Space))
{
// Store the input axes.
float h = Input.GetAxisRaw(“Horizontal”);
float v = Input.GetAxisRaw(“Vertical”);
// Move the player around the scene.
Move(h, v);
}
}