Enabling Javascript, Cookies and Java may be a security hazard as these features allow web sites to do some things with your computer. So why should you enable them for browsing the JCU web site?
Javascript
Javascript is used in internal JCU web applications to make things easier for you the user. This may be something simple such as checking that you have filled in a web form completely or it may be an expanding view of very complex information that allows you to look in detail at parts of the information without having to go to yet another webpage.
Cookies
Cookies are used to save you having to re-type your username and password each time you visit a page in web applications that are not available to the general public and it may keep track of where you are in that application. After the first time, your web browser gets a cookie from the JCU web that when you go to another page it lets the application know who you are and allows the application know what you are doing.
Java
Though not as commonly used as the previous two, having Java enabled in your browser lets the web site send you small applications (applets) that allow you to do some things that normal web pages cannot.