How do i fix my blackberry curve, it wont send SMS messages anymore?

I was texing a friend when I came up with a 'x' saying 'Facility Rejected', this morning I could send SMS messages fine, but the it wouldn't send and now won't send to anybody else, I also don't think I can receive messages, but I'm not sure. please help, need to get texting again ASAP!!!!!! HELP!!!! ;'