
function SetOpacity(elem, opacityAsInt)
{
	var opacityAsDecimal = opacityAsInt;
	
	if (opacityAsInt > 100)
		opacityAsInt = opacityAsDecimal = 100; 
	else if (opacityAsInt < 0)
		opacityAsInt = opacityAsDecimal = 0; 
	
	opacityAsDecimal /= 100;
	if (opacityAsInt < 1)
		opacityAsInt = 1; // IE7 bug, text smoothing cuts out if 0
	
	elem.style.opacity = opacityAsDecimal;
	elem.style.filter  = "alpha(opacity=" + opacityAsInt + ")";
}

function FadeOpacity(elemId, fromOpacity, toOpacity, time, fps)
{
	var steps = Math.ceil(fps * (time / 1000));
	var delta = (toOpacity - fromOpacity) / steps;
	
	FadeOpacityStep(elemId, 0, steps, fromOpacity, delta, (time / steps));
}

function FadeOpacityStep(elemId, stepNum, steps, fromOpacity, delta, timePerStep)
{
    SetOpacity(document.getElementById(elemId), Math.round(parseInt(fromOpacity) + (delta * stepNum)));

    if (stepNum < steps)
        setTimeout("FadeOpacityStep('" + elemId + "', " + (stepNum+1) + ", " + steps + ", " + fromOpacity + ", " + delta + ", " + timePerStep + ");", timePerStep);
}

function getElementsByClass(searchClass,node,tag) {
	var classElements = new Array();
	if ( node == null )
		node = document;
	if ( tag == null )
		tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp('(^|\\\\s)'+searchClass+'(\\\\s|$)');
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}

shuffle = function(o){ //v1.0
	for(var j, x, i = o.length; i; j = parseInt(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
	return o;
};

function loopOpacity(elemId, fromOpacity, toOpacity, time, fps)
{
	var steps = Math.ceil(fps * (time / 1000));
	var delta = (toOpacity - fromOpacity) / steps;
	
	loopOpacityStep(elemId, 0, steps, fromOpacity, delta, (time / steps));
}

function loopOpacityStep(elemId, stepNum, steps, fromOpacity, delta, timePerStep)
{
    SetOpacity(document.getElementById(elemId), Math.round(parseInt(fromOpacity) + (delta * stepNum)));

    if (stepNum < steps)
        setTimeout("loopOpacityStep('" + elemId + "', " + (stepNum+1) + ", " + steps + ", " + fromOpacity + ", " + delta + ", " + timePerStep + ");", timePerStep);
        
       if (stepNum == steps) {
        var rand_no = Math.floor((2500-0)*Math.random());
        if ( rand_no < 500 )
        	rand_no = 500;
        if ( fromOpacity == 0 )
       		loopOpacity(elemId, 100, 0, (rand_no*2), 18);
       	else
       		loopOpacity(elemId, 0, 100, (rand_no*2), 18);
       	
       	}
        
}
