How can I store transform.rotation z value in this case?

I want to save rotation z value when mouse button down and rotate while drag with angle(float).
With this code, gameObject which I want to rotate's rotation z value is change right after click.
How can I get z value?
FYI, the value 'angle' is 0 when drag start.

Code (CSharp):

1. private void Update()
2.     {
3.         if (Input.GetMouseButtonDown(0))
4.         {
5.             zValue = transform.localEulerAngles.z;
6.         }
7.         if (Input.GetMouseButton(0))
8.         {
9.             transform.rotation = Quaternion.Euler(0, 0, zValue - angle);
10.         }
11.     }

 

Never mind
I changed my code like below and it works

Code (CSharp):

1. if (Input.GetMouseButtonDown(0))
2.         {
3.             zValue = transform.rotation.eulerAngles.z;
4.         }
5.         if (Input.GetMouseButton(0))
6.         {
7.             transform.eulerAngles = Vector3.forward * (zValue - angle)
8.         }

 

Oh I didn't think about that at all. Thank you for your advice.