Select box not fire onscroll event on IE 6.0

Hello All,

I have using select box with onscroll event is not fire in IE 6.0 but it is working on IE 7.0 as well as in firefox

<select id="uxName" onscroll="LoadNextItem" multiple size="5">
</select>

javascript:--
function LoadNextItem()
{
alert('hi');
}

what i have do when user scroll down i want to load next 5 item through Javascript that was done in IE 7 as well as in firefox but that issue occure in IE 6 because IE 6 does not work onscroll event so how i can handle that situation Please provide soultion for that.

Thanks in Advance,