sql connection

Question

need to make remote connection in sql server 2008 r2 in c#.

 

following error occur

 A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible.

Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 -

Could not open a connection to SQL Server)