Is this snake poisonous small black snake no stripe on belly whit ring around neck?

It sounds like you might be describing a juvenile or non-venomous snake, as most small black snakes without stripes and with a ring around the neck are not poisonous. However, some species, like the black ringneck snake, can have similar characteristics. It's important to remember that while many snakes are non-venomous, some can be harmful, so it's best to observe from a distance and avoid handling them. If you're unsure, consulting a local wildlife expert or guide can provide more information.