VARCHAR problem?

I know that this is probably very simple but I am having problems with VARCHAR what I want to be able to do is write as short sentance about a course evaluation = how can I do this so it allows spaces in the words etc?

evaluation VARCHAR (20) );

this is what i have at the moment....but i can't write with spaces between my words?

VARCHAR has nothing to do with spaces -- a space is just another string character. I would raise the char limit on it past 20, though -- even short sentences can hit 20 characters pretty easily. And if you have something shorter, memory won't use the extra space.

Exactly what's happening when you try to insert? Also, please post the query you're using.