Colorado Lawyer Box

My friend has two boys with his ex, a 4-year and 5 years old. My friend is not yet divorced, but complete the work with legal counsel to the process. The problem comes when the vengeful ex-wife told me that she wants the children live in Colorado. Of course, he said, because they shared custody now. But since they do not separate, and nothing is rigid in what relates to his rights, so we have very little knowledge about what can happen. People have told him that it can not know what to do it, because she has every right and the court, helping her to walk, although he does not approve. If so, with the false name of justice. Please, the widest possible information about this topic very helpful! Words "kidnapping" comes to mind? I have joint custody with my exhusband with our sons. I can now say that as long as he pays maintenance and court records, it would take the children.