Hover text for input boxes and dropdown lists

Consider the following javascript:

http://orbitsimulator.com/gravity/articles/period1.html

When you hold the mouse over any of the input boxes, you get hover text. For example, the topmost box says "semi-major axis" when the mouse is placed over the box.

In the code <input type="text" name="ip1" id="ip1" onkeyup="f()" title="semi-major axis">
the title tells it the hover text.

But the code that generates the dropdown list next to this input box also has a title <select name="Uip1" id="Uip1" onchange="f()" title="Units">
So I would expect that the word "Units" would appear if I hovered the mouse over the dropdown list, but it does not (at least not in IE6). How can I make the hovertext work for the dropdown lists?

Unfortunately, title does not work in select or option tags in IE unlike in Firefox. I don't know why is it like that. Select element in IE has other special limitations such as floating div obscured under select, CSS style limitation of option tags, onmouseover/onclick in option tag not supported. This is probably because select box is a Windowed control whatever that means.