using UnityEngine;
using System.Collections;
public class anim_sword : MonoBehaviour {
     public AnimationClip bit_1;

     void Update() {
         if(Input.GetButton ("Fire1")) {
             animation.clip = bit_1;
             animation.Play();
         }
     }
}  

if (Input.GetKeyDown("left ctrl"))
      animation.CrossFade("SitDown");
else if (Input.GetKey("left ctrl") && !animation.isPlaying)
      animation.CrossFade("SitIdle");
else  animation.CrossFade("SitUp");