How to set Player to push only during pushing animation

Hey Guys

I've setup my script so that I can push a crate and it works, however it pushes simply when I walk into it, I've managed to edit it so that it now pushes when using the push animation (Holding "Fire1"), and pushes much slower according to my pushing speed.

However I can't work out how to set it so that it only moves when I'm pushing it intentionally.

I've placed my script below, if anyone has any advice It'd be greatly appreciated.

     // this script pushes all rigidbodies that the character touches
     var pushPower = 2.0;
     var weight = 6.0;
      
     function OnControllerColliderHit (hit : ControllerColliderHit)
     {
     var body : Rigidbody = hit.collider.attachedRigidbody;
     var force : Vector3;
      
     // no rigidbody
     if (body == null || body.isKinematic) { return; }
      
     // We use gravity and weight to push things down, we use
     // our velocity and push power to push things other directions
     if (hit.moveDirection.y < -0.3 && Input.GetButton ( "Fire1" )) {
     force = Vector3 (0.1, -0.5, 0) * 1 * weight;
     } else {
     force = hit.controller.velocity * pushPower;
     }
      
     // Apply the push
     body.AddForceAtPosition(force, hit.point);
     }