Almost any condition in a divorce decree can be modified if the movant can show a substantial change of condition and that the change is in the best interests of the children. More facts are needed to opine on this situation. If you wish, e-mail me with more details.
Read the last answer and give us some details. Moving out of state is more complicated and there is a detailed statute for that issue. Call or e-mail an attorney, but appointments always elicit better information for the attorney. As always, be nice to the ex, 'cause you are probably going to be in this legal relationship for a longer span of time than my clients ever go to jail for.
I would need more information. There are many reasons a court would grant such a petition, but they are fact intensive, and I would need to know more. Feel free to e mail me with details.