I loose my domain name

Hi,
by careless mistake i loose one of my domain name... What about the content , if i buy a new one and put the content on it, what will happen ? does google will reindexe this content ?

Is the old content still up?

someone took it but it's like a parking page

Can i set a new website with the old content ?

Sure, if you have a backup of the content or can get a copy from the hosting company, you can put the old content up. Also, if the domain name was one you really liked or had some ranking and stuff fo, you might want to check if it's in "redemption status". That's a period when the name has lapsed but is still being held by the registrar (and yeah, they'd very likely put a parked page up on it and obscure the whois data). If it is in redemption status you can get it back pretty easily (for a fee from the registrar, of course). Just a thought in case you really want the old name back. Feel free to ping me if you would like more help looking at the details of the domain name.