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 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)
}

function blendimage(div1, div2, imagefile, millisec,op) {
	var speed = Math.round(millisec / 100);
	var timer = 0;

	//set the current image as background

	//make image transparent
	currentOpac( div1,0,500);

	//make new image
	setTimeout("document.getElementById(\'"+div2+"\').style.background = '"+imagefile+"'",100);

	//fade in image
	for(i = 0; i <= op; i++) {
		setTimeout("changeOpac(" + i + ",'"+div2+"')",(timer * speed));
		timer++;
	}
	bg1 = document.getElementById(div1).style.background;
	bg2 = document.getElementById(div2).style.background;

	document.getElementById(div1).style.background = bg2;
	document.getElementById(div2).style.background = bg1;
	changeOpac(op,div1);
	changeOpac(0,div2);

}