another computer is using your ip address

Guys it's my second day with my first mac ever. i faced that message "mac another computer is using your ip address" so what does it stand for
i mean the internet router is already mine so where is the problem?

Do you have a iPhone or ANYTHIING else connected to your Wireless Network ??

I get this every now and then and its nothing to worry about. Just a clash of the router assigning IP addresses to other devices is all. Your Mac will take the next in line or it will give the OTHER device another IP.
Don't worry and go about enjoying your 2 day old Mac

yup actually i've got iPad.
thanks,bro actually i'm so glad to have this piece of diamond