writing service in node.js?

Question

Dear All,

 

can any one expline me how to write a service using node.js and socket.io

 

here i have requirement

 

i have a mobile application when a user was opened get his location and send it server and server send that current location to anether client .

 

so please help me am new to node.js

 

we need to implement in node.js and sockets.io