Okay, I have a couple of folders in my main directory but I cannot access them, when I type in the url I get a 403 Forbidden message. Any idea what is going on here? I can use images and stuff on html pages from these directories but I cannot access the directories directly

I can do this: <img src="directory1/image.gif">
but not this: http://www.mysite.com/directory1 - get a 403 Forbidden error when I try. Whats up?