My itunes/app store account doesn't work?

I have a iphone 4 and i don't know why but today when i tried to download an app it suddenly said that i can't connect to server? What does this mean? I know my apple id and my password and it still says that its wrong: L i have made a new apple id account but it still does not work?

Try connecting to Wi-Fi and having a go that way. If you've made a new Apple ID then anything that you bought using your original Apple ID will be unavailable to you when you're using the new Apple ID.