internet help plzz for game

hey, my internet works but when i get on warcraft 3 and click on battlenet, it says unable to connect, and says i don't have internet or not connected, but sometimes i can connect but then i can't join any games and once i disconnect i can't go back in, heres something that might help, it said once when i tried to play a ladder game i had loss of network connectivity? my internet is working like i can go to websites and i can use aim but i can't connect to battlenet ? plz help