Don't reward the crying behavior. Many moms will nearly fall all over themselves in order to get a child to stop crying. That only encourages the behavior.
Be calm, simple, and matter of fact. And impose a consequence for the crying, something appropriate like "crying will not get you what you want, and because you are crying now you need to sit in the chair until you stop".
Then ignore him. Don't fawn all over him, don't try to make him feel better. No means no, and he needs to learn to accept that and self-soothe when he's upset about not getting his own way.
When he stops crying, welcome him back from his "exile" in his chair with a smile ... but again, don't go falling all over yourself about it - unless you want it happening again and again and again.
at 8:57 AM on Dec. 10, 2010