How does CSS and Java Script help more Dynamic user interfaces?

Answer:

The most common uses of JavaScript and CSS are making live changes, such as showing or hiding certain parts of a navigation menu.

An easy example:

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Menu Item One | Menu Item Two | Menu Item Three

Sub-menu Item One

Sub-menu Item Two

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Lets pretend this is a navigation menu on a webpage. It's plain old text, but we're going to pretend that they have borders, color, and they actually link to somewhere.

We want to make it so then when we mouse over "Menu Item One", the sub-menu items will appear and "drop down" for the user.

At first, everything appears visible to the user. We should make the sub-menu items invisible, and wait for the user to mouse over the Menu Item text.

To do that, we would edit this "page" and make the sub-menu items invisible, using CSS.

Now we add a script, using JavaScript, that says when the mouse inside "Menu Item One", the sub-menu items should appear by changing the CSS of the page. And when the mouse moves away, the script should hide the sub-menus with CSS once more.

That would make the navigation menu a dynamic user interface.

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On a related note, when your coding with HTML, CSS, and JavaScript, you are coding in dHTML. dHTML is not a language, but the art of using the three languages together to make something dynamic - Which the above example is doing.

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