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;
	
	//make image transparent
	changeOpac(0, imageid);
	
	//make new image
	document.getElementById(imageid).src = imagefile;

	//fade in image
	for(i = 0; i <= 100; i++) {
		if (i>10){
			setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
			timer++;
		}
	}
	
}

function swapPort(image_load){
	//tag_title = document.getElementById("portDescTitle");
	//tag_url = document.getElementById("portDescURL");
	tag_image_holder = document.getElementById("portHolder")
	//tag_image_holder.style.marginLeft = x_off;
	//tag_title.innerHTML = "<strong>Client : </strong>" + text1;
	//tag_url.innerHTML = "<strong>Link : </strong><a href=http://" + text2 + " target=_blank>"+text2+"</a>";
	
	blendimage('portMainHolder','portMainImg',image_load,'1500');
}

function swapPortNext(file,id){
	/*image_src = document.portMainImg.src
	image_arr = image_src.split("/");
	image_src = ""
	for(i=0;i<image_arr.length - 1;i++){
		image_src = image_src + image_arr[i] + "/"
	}
	image_file = image_arr[image_arr.length -1];
	image_arr = image_file.split('.')
	image_num = image_arr[0]
	if (image_num < total){
		image_num++;
	}*/
	
	//alert(file)
	
	alink = document.getElementById('imageZoom');
	alink.href = "imageLarger.asp?id=" + id;
	
	image_str = file;
	
	blendimage('portMainHolder','portMainImg',image_str,'2200');
}

function swapPortLast(file){
	/*image_src = document.portMainImg.src
	image_arr = image_src.split("/");
	image_src = ""
	for(i=0;i<image_arr.length - 1;i++){
		image_src = image_src + image_arr[i] + "/"
	}
	image_file = image_arr[image_arr.length -1];
	image_arr = image_file.split('.')
	image_num = image_arr[0]
	if (image_num > 1){
		image_num--;
	}*/
	
	//alert(file)
	
	image_str = file
	
	blendimage('portMainHolder','portMainImg',image_str,'1000');
}