animation only playing for a split second

I found a script online for movement and I liked the way it was set up so I started to mess around with it. My problem is that my "slash" animation only plays for a split second before it switches back to idle. Also some of the transition movements from running back to idle and such are choppy. If anyone knows a fix for either of these it would be greatly appreciated. Thank you

     // Movement Variables:
     private var jumpSpeed:float = 9.0;
     private var gravity:float = 20.0;
     private var runSpeed:float = 5.0;
     private var walkSpeed:float = 1.7;
     private var rotateSpeed:float = 150.0;
     private var grounded:boolean = false;
     private var moveDirection:Vector3 = Vector3.zero;
     private var isWalking:boolean = true;
     private var moveStatus:String = "idle";
 
     private var xSpeed = 250.0;
     private var ySpeed = 120.0;
     private var yMinLimit = -40;
     private var yMaxLimit = 80;
     private var x = 0.0;
     private var y = 0.0;
     var anim : Animator;
      
      
     // -------------------------------------------------------------------------------------------------------------
     // ----------------------------------------------------------- UPDATE ---------------------------------------
     // -------------------------------------------------------------------------------------------------------------
      
     function Update () {
        //
        // Only allow movement and jumps while -----------------  GROUNDED -------------
       anim = GetComponent("Animator");
       if(grounded) {
             moveDirection = new Vector3((Input.GetMouseButton(1) ? Input.GetAxis("Horizontal") : 0),0,Input.GetAxis("Vertical"));
            
             // if moving forward and to the side at the same time, compensate for distance
             // TODO: may be better way to do this?
             if(Input.GetMouseButton(1) && Input.GetAxis("Horizontal") && Input.GetAxis("Vertical")){
                 moveDirection *= .7;
             }
            
             moveDirection = transform.TransformDirection(moveDirection);
             moveDirection *= isWalking ? walkSpeed : runSpeed;
            
             moveStatus = "idle";
             if(moveDirection != Vector3.zero) {
                 moveStatus = isWalking ? "walking" : "running";
                 if (isWalking){
                 anim.Play("Walk");
                 } else {
                     anim.Play("Run");
                 }
             } else {
             anim.Play("Idle");
                 // call IDLE animation here
             }
             // Jump!
             if(Input.GetButton("Jump"))
             {
             anim.Play("Jump");
                 // call JUMP animation here
                 moveDirection.y = jumpSpeed;
             }if(Input.GetKeyDown(KeyCode.Alpha1))
             {
                 anim.Play("slash");
                 // call JUMP animation here
                
             }
         }                                                                   // END "IS GROUNDED"
        
         // Allow turning at anytime. Keep the character facing in the same direction as the Camera if the right mouse button is down.
         if(Input.GetMouseButton(1)) {
             transform.rotation = Quaternion.Euler(0,Camera.main.transform.eulerAngles.y,0);
         } else {
             transform.Rotate(0,Input.GetAxis("Horizontal") * rotateSpeed * Time.deltaTime, 0);
         }
        
         // Toggle walking/running with the T key
         if(Input.GetKeyDown("t"))
             isWalking = !isWalking;
            
         //Apply gravity
         moveDirection.y -= gravity * Time.deltaTime;
         //Move controller
         var controller:CharacterController = GetComponent(CharacterController);
         var flags = controller.Move(moveDirection * Time.deltaTime);
         grounded = (flags && CollisionFlags.Below) != 0;
         }
         static function ClampAngle (angle : float, min : float, max : float) {
        if (angle < -360)
           angle += 360;
        if (angle > 360)
           angle -= 360;
        return Mathf.Clamp (angle, min, max);
     }
      
     // -------------------------------------------------------------------------------------------------------------
     // ----------------------------------------------------------- END UPDATE  --------------------------------
     // -------------------------------------------------------------------------------------------------------------
      
     @script RequireComponent(CharacterController)