Clearing Cache
From time to time it may be necessary to clear out the cache of your browser.
What is Cache?
When you visit a website some of the documents and images are stored locally on your computer. This might includeimages, html files, javascript, etc. These files are stored locally so when you revisit the website it will load quicker for you and, also, be less taxing on the website because it does not need to resend files you already have.
How do I know if Cache needs to be cleared? Why does Cache have to be cleared?
If you have problems loading a web page, or it seems out of date, the best first step is to clear your cache. If awebsite has been updated since your last visit there sometimes can be problems loading that new information and yourbrowser will instead rely on the cached version. Also, if a website fails to load properly it is a good indication the cachehas been damaged.
Instructions for Firefox Browser
Press Command + Shift + Delete keys
Make sure Cookies and Cache are checked and then press the Clear Now button. Or
Select the Menu button 
(upper right).
Click Preferences
Click Advanced
To the right of Cached Web Content click the Clear Now button.
Instructions for Google Chrome Browser
Press Command + Shift + Delete keys Or
Click the Menu button 
(upper right) Click More Tools
Click Clear Browsing Data
Everything should be checked accept Password. Click the Clear browsing data button.
Instructions for Safari Browser
Click Safari (upper left) and then Preferences
Click the Privacy tab
Make sure Allow from websites I visit is checked and click the Remove All Website Data button.