Help with animations? Please

Hello I just started a 2D project in Unity, But I have problems with the animations, what happens is that when I move to some side the animation does not stop, that is to say that it continues although I no longer press the button, I am using this code:

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

public class MovimientoAnimado : MonoBehaviour {

 Rigidbody2D rbody;
 Animator anim;

 // Use this for initialization
 void Start () {

     rbody = GetComponent<Rigidbody2D> ();
     anim = GetComponent<Animator> ();

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

     Vector2 movimiento_vector = new Vector2 (Input.GetAxisRaw ("Horizontal"), Input.GetAxisRaw ("Vertical"));

     if (movimiento_vector != Vector2.zero){
         anim.SetBool ("caminando", true);
         anim.SetFloat ("presiona_x", movimiento_vector.x);
         anim.SetFloat ("presiona_y", movimiento_vector.y);
     }
     else
     {
         anim.SetBool ("caminando", false);
     }

     rbody.MovePosition (rbody.position + movimiento_vector * Time.deltaTime);
 }

}

Also marks me 2 errors:

Parameter 'caminando' does not exist. UnityEngine.Animator:SetBool(String, Boolean) MovimientoAnimado:Update() (at Assets/An/MovimientoAnimado.cs:30)

and

Parameter 'caminando' does not exist. UnityEngine.Animator:SetBool(String, Boolean) MovimientoAnimado:Update() (at Assets/An/MovimientoAnimado.cs:24)

If they could help me I would appreciate them (Sorry if something is misspelled, I do not speak English and I translated it with Google.)