1.)  If you don't remember your user name and password, click the "forgot your password?" link in the login box. You can have your password reset and login information emailed to you.

2.)  If you are SURE you are entering the correct login information and it STILL doesn't work, this is almost always due to old or incorrect login information stored in your web browser. Deleting cookies and browser cache will correct this issue.

• Internet Explorer 7 - Go to Tools --> Internet Options then click the "Delete..." button in the Browsing History section. You can then click the "Delete Files" and "Delete Cookies" buttons.
  
  
• Internet Explorer 6 - Go to Tools --> Internet Options and click the buttons to delete cookies and offline content.
  
  
• Firefox - Go to Tools --> Options and click the "Cache" tab to click the "Clear Cache Now" button then the Cookies tab to clear your browser cookies.