For PC Users:
In Explorer, go to Tools>Internet Options. Under the General tab, in the Temporary Internet Files section, click clean files and then click clean cookies.
Also, click on settings and under the Check for newer versions of Stored Pages heading, make sure the Every visit to the page is selected. It is a good idea to clean your cache and cookies often, depending on how often you use the Internet. If you are a heavy user, it is advisable to clean them every few days.
Firefox users click on Tools > Options > Privacy Tab> Clear Cookies and Tools > Clear Private Data > Select: Browser History, Cache, Cookies>Clear Private Data Now.
For MAC Users
If you are using Internet Explorer, click on Preferences from the drop-down menu. At the next dialog box, use the scroll bar on the left-hand menu to locate the Web Browser heading and click Advanced. The Cache section will appear on the right-side content are. Click the Empty Now button and then click OK.
If you are using Safari, pull down the Safari menu; select Empty Cache on the drop-down menu; click OK.