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);
	}
}

// Always requires a relative div wrapping the image
function blendimage( imageid, imagefile, millisec) 
{
	var speed = Math.round(millisec / 100);
	var timer = 0;
	var image = document.getElementById(imageid);
	var imageDiv = image.parentNode;
	
	imageDiv.innerHTML += '<img id="imageblender" class="' + image.className + '" src="' + imagefile + '" style="position: absolute; top:0; left: 0; opacity: 0; filter: alpha( opacity=0 ); " /></a>';

	//fade in image
	for( var i = 0; i <= 100; i++ )
	{
		setTimeout( "changeOpac(" + i + ",'imageblender')" , timer * speed );
		setTimeout( "changeOpac(" + (100-i) + ",'" + imageid + "')" , timer * speed );
		timer++;
	}
	
	setTimeout( 'var image = document.getElementById( "' + imageid + '" ); image.src = "' + imagefile + '"; changeOpac( 100, image.id ); ', 100*speed );
	setTimeout( 'document.getElementById( "' + imageid + '" ).parentNode.removeChild( document.getElementById( "imageblender" ) );', 110*speed );
}

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)
}