turrent rotation limits

hi trying make 2d turret game the problem i want rotate limit my code

using UnityEngine;
using System.Collections;

public class TurretController : MonoBehaviour {

public float speed;
public float maxaxis =42;
public float minaxis =-42;

void Update () 
{

	if (Input.GetKey(KeyCode.A))
		
    {
		
		transform.Rotate(0,0,speed);

		Vector3 eulerAngles = transform.eulerAngles;
		eulerAngles.z = Mathf.Clamp (eulerAngles.z, minaxis, maxaxis);
		transform.eulerAngles = eulerAngles;	
    }

	if (Input.GetKey (KeyCode.D)) 
	
	{
		transform.Rotate (0, 0, -speed);

		Vector3 eulerAngles = transform.eulerAngles;
		eulerAngles.z = Mathf.Clamp (eulerAngles.z, minaxis, maxaxis);
		transform.eulerAngles = eulerAngles;

}
}

}

Hello there simply add in a line of code somewhere along the lines of

if (transform.rotation.z > maxaxis)
{
    transform.rotation.z = maxaxis;
}
if (transform.rotation.z < minaxis)
{
    transform.rotation.z = minaxis;
}

I hope this helps!