Making kids happy

I heard a lady say once (and no doubt this was a wonderful mother, probably much better than I am), "Whenever my kids are unhappy, I tell them, 'It's my job to be a parent; it's not my job to make you happy.'"
While I kind of agree with this sentiment, I also must disagree with it. Parents cannot MAKE a child happy if that child is determined to be unhappy. However, parents can do a great deal to create an environment that makes children happy.
Are the children eating right? Are they getting enough exercise? Enough sleep? Are they sick? Are they getting some unstructured playtime? Are they doing a few simple chores? Are they being praised for a job well done?
Do you allow them to have playmates? Do you monitor this playtime without being too overbearing? Do you have patience? Do you keep your promises? Do you give them lots of attention, even when you are tired? Do you read to them, pray with them? Do you set limits?
Are you too easily critical? Are you expecting too much?

I think it is the job of the parents to create an environment where happiness is the norm, as much as possible!