Do bathing and ablution suffice for purification from major ritual impurity (janabah), and will the 'Asr prayer be valid?

If bathing is done with the intention of performing ghusl (definition) (ritual bath) for janabah (definition) (state of ritual impurity), then it is a valid purification, and prayer after it is permissible, due to the Prophet's (peace and blessings of Allah be upon him) saying: "Indeed, actions are by intentions, and indeed every person will have what he intended." However, if it is merely a habit for cleanliness, it is not considered purification from major ritual impurity, and prayer after it is not permissible.