stop IP from changing

hello,
i have a problem on my hands, i'm making/have made a chat program for windows, with my computer being the server. I Have cable, but sometimes my IP will change without warning, it could be in two days or two months, which means all people who will try to connect to my chat server will be stuck without my IP. So what i'm looking to do is either stop my IP from changing, or when it does change, find some way to inform all client programs that my IP has changed so they goto 'someplace' to get my Ip.

which way is possible?(if any)
does anybody have another idea of how to resolve this problem?

Two ways to solve this:
1) Contact your cable provider and ask them for a static ip address. They will most likely have a monthly charge for this.
2) Look into some of the company's that provide free dynamic DNS services. Most require you subdomain off of them but thats ok. Then you just use a domain name instead of an IP address.

thanks, i took suggestion 2, and it's now working :)

just got another question:

when i'm waiting for a client to connect using accept()
my program is using about 99% cpu, why so much? is this a problem?

What does your code look like?

stupid me, i just found the problem, and it was totaly unrelated to the accept() function.
sorry