how old are your kids?...if your wife would agree that u can take them then there will be no problem...but if she wont then thats a real big problem..if the kids are under 7 years old the custody of the child always get by the mother (unless u prove the authority that she is not a good mother to her kids)..then when they reach the age of seven the court would then let the kids to choose whom they want to stay with either with mother or father...hope that helps
