My ex-husband and I got divorced in 2001 ,we agreed without the involvement that I get sole physical custody and he gets visitations ,in 2003 I got his verbal OK to relocate to Washington state (our divorce agreement said written but we were and still are civil with each other)i lived there with my kids till 07 ,they saw him 104 days out of the year ,talked on the phone every day plus saw him via web cam 4 times a week,the kids were doing great in school ,they had good friends and adjusting very well to live in the northwest,in jan 07 I was diagnosed with pericardial effusion that left me tired all the time plus edema in my hand and feet ,so I asked him to look after the kids till I became well,in the summer of that year he refused to return my kids I tried for several months to convince him with no success,so I quit my job borrowed money from my mom and moved back to cali,the kids were dropped off 4 hours after I arrived even though I was staying in a hotel ,I've been looking for a job since November 07 I maxed out my credit cards and late on my bills ,I had to take out a loan just to survive.I tried to explain to him that financially I can't make it in California ,so after many attempts to solve this matter without the court getting involved in our personal business I've decided to take legal actions,he said that we do not have to hire lawyers and that we could just go in front of the judge and arrgue aour case ,he sees the kids once sometimes twice aweek with no over night visits ,we are still communicating and I have never or will ever deny him visitations ,I also offered to pay 50%of the travel expences and any other fees he needed once thekids came to visit .but he refused ,so I want to ask ,will it hurt me since I am unable to fine ajob or that I'm in debt because of this move ,and what are my chances of winning

Assuming his is using his visits it is likely the judge would not allow a move very far away. But one never knows all you can do is try.
The only thing you have going for you, is he allow you to move before, if you can prove he gave his permission, and does not claim you did this without permission.

Most likely the courts may allow if you increased the time of his visitation and paid 100 percent, since it is for your benefit, not his for the move, the courts may want to know why he should have to pay anything since if you live here you don't have to pay anything.
Now if you told him that OK, you keep the kids, and I will move without them, would he want him, or is this more of a bluff to control you?