I am the custodial parent of my 6 year old child, I would like to relocate within the state.

I am interested in moving (in state) with my 6 year old child. I am the custodial parent. The father sees him for a total of about 1 1/2 days per week. This is something we have agreed upon ourselves, we have not involved the courts. He pays monthly court ordered child support. Where i'm planning to move is about an hour and a half, maybe 2 hours away. I want to know what steps to take in going about this, what he could potentially do to try and stop me and what measures to take in order to prevent that from happening if need be. I am not trying to stop his father from seeing him, I am planning on moving to a place that I feel suits us better and has better opportunities for me to grow financially. If it helps, his father abandoned him when he was 10 months old and I was forced to go through the courts to receive child support. He ended up returning when my son was around 3 years old and has been a part of his life ever since. I have not spoken to him of these plans yet.