Changing the e-mail on the iPod Touch?

Ok, so I recently used the little 'e-mail' app on the iTouch and it worked great for a while, but now every time I try to check my mail on it, it says that the password is incorrect. I've been trying to fix it but I have no idea how. Anyone know?Changing the e-mail on the iPod Touch?you just adjust it just you go into settings