var ie = document.all;

var fadeInterval;
var fadeStartValue = 1;
var fadeStopValue = 0;
var fadeStepDelay = 20;
var fadeStep = 0.05;
var ieFadeCoef = 100;

function fadeStepFct(elementId, pFadeStep, pFadeInterval)
{
	opacity = getOpacity(elementId);
	if (isNaN(opacity))
		opacity = fadeStartValue;
	if (document.all)
		opacity += Math.floor(pFadeStep * ieFadeCoef);
	else
		opacity += pFadeStep;
	setOpacity(elementId, opacity);
	opacity = getOpacity(elementId);
	if ((pFadeStep < 0 && opacity <= fadeStopValue) ||
		(pFadeStep > 0 && opacity >= fadeStopValue) ||
		(pFadeStep == 0))
		clearInterval(pFadeInterval);
}

function fade(elementId, pFadeStopValue)
{
	clearInterval(fadeInterval);
	fadeStopValue = pFadeStopValue;
	opacity = getOpacity(elementId);
	pFadeStep = Math.abs(fadeStep);
	if (opacity > fadeStopValue)
		pFadeStep = -pFadeStep;
	fadeInterval = setInterval('fadeStepFct("'+elementId+'", '+pFadeStep+', fadeInterval)', fadeStepDelay)
}

function getOpacity(element)
{
	if (ie)
	{
		return parseFloat(document.getElementById(element).filters[0].opacity);
	}
	else
		return parseFloat(document.getElementById(element).style.opacity);
}
function setOpacity(element, opacity)
{
	if (ie)
	{
		document.getElementById(element).filters[0].opacity = opacity * ieFadeCoef;
	}
	else
		document.getElementById(element).style.opacity = opacity;
}

function fog_all_pics()
{
	for (i = 0; i < pic_dimension.length; i++)
	{
		setOpacity("img_pic_" + i, minOpacity);
	}
}