function opacity(id, opacStart, opacEnd, millisec) 
	{
	//speed for each frame
	var speed = Math.round(millisec / 100);
	var timer = 0;

	//determine the direction for the blending, if start and end are the same nothing happens
	if (opacStart > opacEnd) 
		{
		for (i = opacStart; i >= opacEnd; i--) 
			{
			setTimeout("changeOpac(" + i + ",'" + id + "')", (timer * speed));
			timer++;
			}
		}
	else if (opacStart < opacEnd) 
		{
		for (i = opacStart; i <= opacEnd; i++) 
			{
			setTimeout("changeOpac(" + i + ",'" + id + "')", (timer * speed));
			timer++;
			}
		}
	}

//change the opacity for different browsers
function changeOpac(opacity, id)
	{
	var object = document.getElementById(id).style;
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity=" + opacity + ")";
	}

function shiftOpacity(id, millisec)
	{
	//if an element is invisible, make it visible, else make it ivisible
	if (document.getElementById(id).style.opacity == 0)
		{
		opacity(id, 0, 100, millisec);
		}
	else
		{
		opacity(id, 100, 0, millisec);
		}
	}

function blendimage(divid, imageid, imagefile, millisec) 
	{
	var speed = Math.round(millisec / 100);
	var timer = 0;

	//set the current image as background
	document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";

	//make image transparent
	changeOpac(0, imageid);

	//make new image
	document.getElementById(imageid).src = imagefile;

	//fade in image
	for (i = 0; i <= 100; i++)
		{
		setTimeout("changeOpac(" + i + ",'" + imageid + "')", (timer * speed));
		timer++;
		}
	}

function currentOpac(id, opacEnd, millisec)
	{
	//standard opacity is 100
	var currentOpac = 100;

	//if the element has an opacity set, get it
	if (document.getElementById(id).style.opacity < 100) 
		{
		currentOpac = document.getElementById(id).style.opacity * 100;
		}
	//call for the function that changes the opacity
	opacity(id, currentOpac, opacEnd, millisec)
	}