Is there any secret to making baby lay in a crib?....

He's got this thing, that he wants to stand up all the time. When I lay him down, he rolls over to his belly, and pulls himself up.

The little monkey won't go to sleep for me!!.. It probably takes a good hour of me going in there and laying him back down mulitple times.
Some times I just get frustrated and get him up, and let him play longer, but I think thats what he is waiting for, so I am trying not to do it.

He just stands there, in his crib...In the darkness......When I tip toe down the hall and peek in his room...He giggles....And thinks its funny.