Help me name that movie : Movie I saw in the 60's

[Janie Scott]

I saw a movie when I was little and all I remember is it was some kind of western where some guy has to kill some other guy who killed his brother or father. The unusual thing (and all I remember) was that when the guys gang was asked why they had to kill the other guy they all lifted their hats and said "It's the western way".
Does anyone know what this movie is?