This document would demand that your ex appear in court and explain to the judge why he shouldn't have to tell you where he plans to take the kids. He wants to relocate 600 miles away for a better job. If they move, I could only afford to see my child every few months. That depends on which state's law governs. It's usually the state where your divorce was issued, or where the child currently resides.
States vary widely when it comes to rules about relocation.
Some states allow parents with physical custody to relocate with the child no matter how much distance is involved. Others favor the rights of the non-custodial parent to maintain an ongoing relationship with his or her child, and are reluctant to allow such moves. Some courts require the moving parent to have a job, secure a home and select the child's school before moving. Before going to court, try talking to your ex-husband. Explain your financial situation and how it will affect your ability to see your daughter.