CSS: How to prevent long text from spilling out of the container

I would like to ask how I can prevent text spilling out of a div container  if someone does something like this : vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

because it won't wordwrap as there is no space.. so what happens it just spills over and runs across the other parts of the page.

Thanks a lot for your input in advance