What would you say to your boss if he is crazy about an idea, but you think it stinks?

Boss is always right, because his or her knowledge much more better then me, my experience says that any idea which I feeling as crazy, this is actually not like that. Because I'm watching a part of that idea not watching the overall of that idea or plan.

Everyone has different point of view on same matter,it is not necessary to match up with our seniors . so i will express my point view with him/her.

There is a way to put it across, I never tell him on the face that the idea is not good. I rather tell him what alternative could be done and if he is okay with that?

It makes lot of difference between saying "You know what your idea is not good at all!"

And saying "Sir, WHy don't we do this instead of that? don't you think it could be more effective?"

Sir, I clearly understand which way you are heading but it would be great if we take a bird eye view on the entire scenerio rather than focusing on only the positive aspects of the project