How do I access the current style of an element?

HTML page elements in IE4+ and NN6 have a style object property with sub properties for all the css style attributes the browser supports

e.g.
elementRef.style.color for the text color
elementRef.style.fontSize for the font size.

This style object is however not giving you the computed/cascaded style of an element but is (initially) only a reflection of the inline style set on an element and later only reflecting what you assign to it.

ie
<P STYLE="color: orange;" ONCLICK="alert(this.style.color)" >
shows you the string orange while <P ONCLICK="alert(this.style.color)">
shows you an empty string as the inline style color value is empty.

So how do you get the current computed/cascaded style of an element, in particular for elements which don't have an inline style? IE5 has
support for that with introducing the currentStyle object property for HTML page elements. Contrary to the style
object the currentStyle gives you a value for all elements, whether they have an inline style, a style class, a named style rule or no
style setting at all inheriting its styles from the document body.

Try the following with IE5 and you will see the difference between the currentStyle and the style object: