Hi... Would like some info if anyone knows the answer?

[kcfaz]

Hi my name is Casie (kc) I'm in the UK so this is for any one who knows the uk rules for my problem.
The problem is with my eldest son. I had him when I was 18 in 1998, since then and up until about 6-8 months ago his dad has been less than useless, he has only ever lived no more than five minutes away from us but has always allowed either the drink or his current girlfriend or wife to be the dictator as to how much he sees his son and how useless he is when he was with him.
However besides all this contact started up again about 6-8 months back for the umpteenth time and with another new girlfriend, and it's all been going well. Throughout all of my sons life I have had extreme problems with his behavior and just recently our relationship has hit a cross roads. I was speaking to him a while ago and the conclusion of of this talk was that he thought that there had to be more to life than what I was offering him (philisophical little so and so!!!), so I started thinking that just maybe if he spent some time with his dad he might just realise that living with us is not all that bad, all it involves is a little bit of effort from him and we can all get along resonably fine.
I never once thought his dad would go for it but he did so we all agreed on a two month trial which at the end if this he had a decission to make as to where he wanted to live. Of course I was hoping it would be with me my husband and his brother, unfortunately after only two weeks he has chosen his dad, I am still not doing anything until January as originally planned, my hope is is that the novelty will wear off by then and he will want to come back home!!!
If he doesn't I am willing to let him go, I just need to know before I change all of his details over if I will still retain all the legal rights I have at the moment?
I know in the UK, the system says that if you are not married and never were the dad has no legal rights to the child, they go automatically to the mother, if he wants any he has to apply to the courts for parental rights which I know he has never done. Will my rights still apply even if I let him go and live with his dad, I need to know this so that if he tries to stop me seeing him as we have arranged which is currently every Tues and Thurs after school plus every other weekend will I have the right to take him back or will he have gained some rights by default just by me letting him go?
Please can someone enlighten me I cannot afford to go to a solicitor about this and everything I read tells me my rights if the child stays with me or a dads rights if two parents are separated, supprisingly! it's not often a mother willingly gives her child over to the other parent so there's no info on it.
I am only agreeing to this to help my son, if it is what he really wants and they get the best of him and so do we it has got to be the right choice, well this is what I'm telling myself so it might be a little easier to handle.