I have this domain name www.marinetreat.info and i changed the DNS a few days ago but i get a error and it wont load up.

I emailed http://domain.yarantoos.com/ there are saying it's my host but this is not ture as all other sites are running fine.

Could any one help me find out whats wrong with it please.

* Dns unable to resolve marinetreat.info

That's your first problem.
You have to make an a-record to the server that's hosting the website.
Can you give more specifics about who hosts the dns, if you have control over the dns and if there exists an a-record?