Help with player script.

I have been working on a crouch function for my 2d side scroller. It works,but it stops the attack function from working. Also I have tried to add jumping in there, but I couldn't figure it out. Could some one please help me?

 using UnityEngine;
 using System.Collections;
 using SpriteFactory;
     
 public class player : MonoBehaviour {
     
     
     
     public float speed = 1.0f;
     public float jump = 10.0f;
     public float gravity = 10.0f;
 
         
     private Transform thisTransform;
     private Sprite sprite;
     private bool flipped;
 
     // Use this for initialization
     void Awake () {
         thisTransform = transform;
         sprite = (Sprite)GetComponent(typeof(Sprite));
     
     }
     
     // Update is called once per frame
     void Update () {
         Vector3 moveVector = new Vector3(0,0,0);
         bool moving = false;
         
         
         
     if(Input.GetKey(KeyCode.A)){
             moveVector.x -= 1.0f;
             moving = true;
         
     }
         
         if(Input.GetKey(KeyCode.D)){
             moveVector.x += 1.0f;
             moving = true;
             
             
         }
         
 
         if(Input.GetKey(KeyCode.Mouse0)){
             Attack();
         } else {
             if(!IsAttacking()) {
                 if(moving) {
                     Move(moveVector);
                 } else {
                     Stand();
             }
         }
         }
         if(Input.GetKey(KeyCode.S)){
             Crouch();
         } else {
             if(!IsCrouching()) {
                 if(moving) {
                     Move(moveVector);
                 } else {
             Stand();
     }
     }
         }
     }
         
     
     
 
     
     private void Stand() {
         sprite.Stop();
     }
     
     
     private void Move(Vector3 moveVector) {
         FlipSprite(moveVector.x);
         moveVector *= speed * Time.deltaTime;
         thisTransform.position = thisTransform.position + moveVector;
         sprite.Play("walk");
         
         
         
     
     }
     
     private void FlipSprite(float x) {
         if(x == 0.0f) return;
         
         float xDir = Mathf.Sign(x);
         if(!flipped && xDir < 0.0f) {
             flipped = true;
             sprite.SetFlippedState(true, false);
         } else if(flipped&& xDir > 0.0f) {
             flipped = false;
               sprite.SetFlippedState(false, false);
         }
     }
     
     private void Attack() {
         if(IsAttacking()) return;
         
         sprite.Play("Sword");
     }
     
     private bool IsAttacking() {
         if(sprite.IsAnimationPlaying("Sword")) return false;
         return false;
     
 
 }
     
     private void Crouch() {
         if(IsCrouching()) return;
         
         sprite.Play("crouch");
     }
     
     private bool IsCrouching() {
         if(sprite.IsAnimationPlaying("crouch")) return false;
         return false;
     
 
     
     
 
     
         
     
 }            
         
     
     
 
 
 }