lammert - 12:26 pm on Jun 6, 2010 (gmt 0)
Hi jeet333, welcome to WebmasterWorld!
If your site is reachable when you add the IP address of that site to your local hosts file, but not otherwise, it seems to be a lack of an A record in your DNS settings. The A record translates the name of your domain to the IP address.
Another reason can be that your records in your DNS servers are correct, but that the DNS server is not listening correctly to request from the outside world. Such a situation can happen when a firewall between your server and the Internet is blocking incoming DNS requests. It could also be that the DNS server daemon on your server didn't start correctly. Some hosting companies do not allow running your own DNS server anf block requests to the UDP port 53 where the DNS server is listening by default. The do this because an incorrectly configured DNS server may be used as a proxy for DDOS attacks on other servers.
You can check if your DNS daemon is running if you have SSH access to the server. The command netstat -nl will produce a list of all the running network daemons. You should see a line like:
udp 0 0 0.0.0.0:53 0.0.0.0:* LISTEN
udp 0 0 :::53 :::* LISTEN