You can fix it, but you'll probably need a special tool to re-attach a snap button. Here are some links to take a look at:
http://www.doityourself.com/forum/sewing-quilting-needlework/287157-snap-button-repair.htmlhttp://www.ehow.com/how_7163448_replace-snap-button.htmlIf you don't want to buy the tool and try to figure it out, I bet it's a really cheap fix that a dry cleaner or tailor could do for you. Good luck!