fadeTime = 400;
fadeMin = 0.0;
fadeMax = 1.0;
fadeRate = 0;

function fade(id, time, min, max, rate, lastTick) {
        var tick = new Date().getTime();
        var element = document.getElementById(id);
		 if(element == null) return;

        if (element.fadeState) 
		{
                if (lastTick)
                        element.fadeTimeElapsed += tick-lastTick;
                else {
                        element.fadeState = element.fadeState == 1 ? -1 : 1;
                        element.fadeTimeElapsed = element.fadeTime-element.fadeTimeElapsed;
                        if (time != null) {
                                element.fadeTimeElapsed = element.fadeTimeElapsed/element.fadeTime*time;
                                element.fadeTime = time;
                        }
                        return;
                }
        }
        else {
                element.fadeTime = time != null ? time : element.fadeTime != null ? element.fadeTime : fadeTime;
                element.fadeMin = min != null ? min : element.fadeMin != null ? element.fadeMin : fadeMin;
                element.fadeMax = max != null ? max : element.fadeMax != null ? element.fadeMax : fadeMax;
                element.fadeRate = rate != null ? rate : element.fadeRate != null ? element.fadeRate : fadeRate;
                element.fadeState = element.style.opacity == element.fadeMax ? -1 : 1;
                element.fadeTimeElapsed = 0.0;
        }
        var opacity = element.fadeTimeElapsed/element.fadeTime;
        if (element.fadeTimeElapsed >= element.fadeTime)
                opacity = 1.0;
        if (element.fadeState == -1)
                opacity = 1.0-opacity;
        opacity = (element.fadeMax-element.fadeMin)*opacity+element.fadeMin;
        element.style.opacity = opacity;
        element.style.filter = 'alpha(opacity='+opacity*90+')';// IE
        if (element.fadeTimeElapsed >= element.fadeTime)
                element.fadeState = null;
        else
                setTimeout("fade('"+id+"', null, null, null, null, "+tick+")", element.fadeRate);
}

window.onload=function(){
fade('box1', 1000, null, 0.7, 33);
fade('box2', 1000, null, 1.0, 33);
fade('box3', 1500, null, 0.7, 33);


}