unity unet and ui

Can anyone tell me how i can disable an ui button if i am a server and enable the ui button if i am a client?

Thanks in advance.

If you are using the legacy networking system :

button.SetActive( !Network.isServer ) ;

If you are using Unet :

// Supposing the gameobject holding the script has a NetworkIdentity component
button.SetActive( !GetComponent<NetworkIdentity>().isServer ) ;