In Civilization IV, what do I do when the citizens of my city say it's too crowded?

Also, how do I get gold?In Civilization IV, what do I do when the citizens of my city say it's too crowded?
the 'too crowded' unhappiness is just the default malcontent. if you're at war, people ,ight demand peace, if you don't have any troops protecting the city, they will complain about that, certain building will make people unhappy.

the too crowded thing is just the one thing they're unhappy with if they have nothing else to complain about. if you have solved all the other issues, just make sure that the citizens have access to something that makes the happy (certain resources, religious buildings, other buildings etc.) and there won't be a problem