Getting ip address of the remote computer

Hi all there,
I am developing an application to automatically transfer the file from my computer to the remote computer and both computer are connected to the internet. How can i find the IP address of the remote computer to which i want to send a file.
How can i find that the computer to which i want to send file is connected to the internet.

[Serge]

What type of application are you writing? Is it web application? If yes, the I can tell you this: if you use ASP then you check the IP by using ServerVariables property of Request object:

Response.Write Request.ServerVariables("REMOTE_HOST")

If you use client application then you can do it by using Winsock control:

MsgBox Winsock1.RemoteHostIP

even i use to ponder over this problem but luckily
i had my own website. This is what i did

whenever the remote computer was online, it
use to post a message on a webpage giving its status
and dynamic ip. Whenever my computer went on it use to access that page and read the ip and establishing a connection with that ip.

if you want to know how i did this or use my website as a
the place where you can keep the ip, contact me at:
Yash_VB@hotmail.com