mecanim blend tree attack combo

So im trying to make attack combos, i think using a blend tree would be the solution but i dont know how to do it, i can set up a blend tree, but im lost on the scripting of the combos. Its gonna be like a hack’n slash, the user can spam the attack button to do consecutive attacks, and after the third a pause. If the user does not push the attack button withing a certain amount of time after the previous attack it resets.

Something like this?

using UnityEngine;
using System.Collections;

public class test3 : MonoBehaviour {

	public float time = 3.0f;
	public Animator anim;
	public float Attack;
	public bool startTimer;

	void Start () {
		anim = GetComponent<Animator> ();
	}

	void Update () {
	

		if (Input.GetButton ("Fire1") && time > 0) {
			Attack++;
			startTimer = true;
		} else if (time <= 0.0f) {
			Attack = 0.0f;
		}
		anim.SetFloat ("FloatName", Attack);

		if (startTimer) {
			if(time >= 0){
				time -= Time.deltaTime;
			}else if (time <= 0){
				time = 3.0f;
				startTimer = false;
			}
		}
	}
}

if (Input.GetButton (“Fire1”) && time > 0)
{
Attack++;
startTimer = true;
} else if (time <= 0.0f) {
Attack = 0.0f;
time = 3.0f;
startTimer = false;
}
anim.SetFloat (“FloatName”, Attack);
if (startTimer) {
timer -= Time.deltaTime;
}

Pretty sure this would yield the same. Plus <= in else if would never trigger cause >= is in if statement.