hit gameobject tag

I use a raycast in my gun script and if it hits a gameobject with the tagg zombie it has to send a message to that gameobject to apply damage I can send messages and detect if somthing is hit but it doesn’t recognise the tag.
here is my code to detect the hit:

if (Physics.Raycast(transform.position, fwd, 10)&& tag == Zomie) { 

Tags are Strings.

tag == "Zombie"

Tags must be defined in the Tag manager.

I already added the tag but it doesn’t detect it