Just ask Kijiji, a classifieds site that is fairly popular in French speaking Canada. Let’s say you have just filled out the ad submission form and hit submit. What do you think the message says that I’ve blurred out in the red box?
Very easy! It obviously says:
Thank you for having posted your ad.
What other message would a red box with a red X contain on a page like this, after a user has just pressed submit?!