how to connect client on one machine with server

i have made a program in java. when the client and server are one machine they communicate very well.but when i tried to connect with server as a client from other machine...i have provided the ip address pf the server machine also... i have connected both computers using lan wire. but it gives an exception ..says either the ip address is not valia or port is not valid on remote machine ...please please please help me..as soon as possible

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Dear pooja13singh,

Please check first that your machine has an access to the other machine , from your cmd , type "ping ip" . If yes ,

Please make sure that your are using the same java NIO classes as in the following chat program .
finished-projects/java-chat-t644.html