// opacity.js

function setOpacity(eID, opacityLevel) 
{
    var eStyle = document.getElementById(eID).style;
    eStyle.opacity = opacityLevel / 100;
    eStyle.filter = 'alpha(opacity='+opacityLevel+')';
}

function fade(eID, startOpacity, stopOpacity, duration) {
    var speed = Math.round(duration / 100);
    var timer = 0;
    if (startOpacity < stopOpacity) { // fade in
        for (var i=startOpacity; i<=stopOpacity; i++) {
            setTimeout("setOpacity('"+eID+"',"+i+")", timer * speed);
            timer++;
        } return;
    }
    for (var i=startOpacity; i>=stopOpacity; i--) { // fade out
        setTimeout("setOpacity('"+eID+"',"+i+")", timer * speed);
        timer++;
    }
}