How to Clear Cookies and Empty your Browser Cache:
Internet Explorer: Under "Tools" on the top menu bar, click on "Internet Options." Under the "Browsing History" heading, click "Delete." Click on "Delete files" and "Delete Cookies," make sure "Every visit to Page" is checked, then click "Close." Restart Internet Explorer and login to the site again.
Mozilla Firefox: Under "Tools" on the top menu bar, click on "Clear Private Data." Select the checkboxes next to "Cookies" and "Cache." Then click "Clear Private Data Now." Restart Firefox and login to the site again.
Safari: Under "Safari" on the top menu bar, click on "Empty Cache." When you see the pop-up warning message, click on "Empty." Then, also under "Safari" on the top menu bar, click on "Preferences." Click on the lock shaped "Security" icon. Click the "Show Cookies" button. Click "Remove All" and then click "Done." Exit the preferences screen. Restart Safari and login to the site again