check if server port is open

1.Download port tester application from this site (download button on the left) .
2.Application has two text-boxes on the top : one for server name or ip another for port.
3.Enter server name and port and click on [Test] button to test specific port on this server.
4.Application will return "Port available" if port is open on this server or will return
connection errors if port or server is unavailable such as "server not found" or "server unavailable".