Lock viewing angles

Hey guys!
I have a problem with my camera controller: the character kan look 360° Around and even inside of himself! how o i lock these variables to how far he can look up and down?

Code (CSharp):

1. public float dpi = 100.0f;
2. public GameObject Cam;
3.  
4.     void Update()
5.  
6.     {
7.         var y = Input.GetAxis("Mouse Y") * Time.deltaTime * -dpi;
8.        
9.         Cam.transform.Rotate(y, 0, 0);

I would be happy if anyone would help me.

 

try mathf.Clamp
https://docs.unity3d.com/ScriptReference/Mathf.Clamp.html

 

Thanks, that is what I have been searching for, but iI always run into problems with the 1st value. what should it be?

 

y = mathf.Clamp(y, min, max);