// JavaScript Document
/* 
	a few concepts were taken form: http://brainerror.net/scripts/javascript/blendtrans/
*/
var timerID = new Array();
var which  = 0;
var which_2 = 0;
var which_3 = 0;
var which_4 = 0;
var loop = 1;
var rotate_time = 2000;
function start() {
	if(loop == 1){
		which += 1;
		if(which > 4 )
		{
			which = 1;
		}
		blendimage('greg_div', 'greg_img', 'greg',rotate_time, which);
		//rob
		blendimage('rob_div', 'rob_img', 'rob', rotate_time, which);
		//blendimage('geoff_div', 'geoff_img', 'geoff',rotate_time, which);
		//blendimage('chelsea_div', 'chelsea_img', 'chelsea',  rotate_time, which);
	}
	else if(loop == 2){
		which_2 += 1;
		if(which_2 > 4 )
		{
			which_2 = 1;
		}
		
		blendimage('amy_div', 'amy_img', 'amy', rotate_time, which_2);
		//chelsea
		blendimage('chelsea_div', 'chelsea_img', 'chelsea',  rotate_time, which_2);
		//blendimage('laura_div', 'laura_img', 'laura', rotate_time, which_2);
	}
	else if(loop == 3){
		which_3 += 1;
		if(which_3 > 4 )
		{
			which_3 = 1;
		}
		blendimage('traci_div', 'traci_img', 'traci', rotate_time, which_3);
		//dana
		blendimage('dana_div', 'dana_img', 'dana', rotate_time, which_3);
		
		//blendimage('ray_div', 'ray_img', 'ray', rotate_time, which_3);
		//blendimage('rob_div', 'rob_img', 'rob', rotate_time, which_3);
	}
	//not used
	else if(loop == 4){
		which_4 += 1;
		if(which_4 > 4 )
		{
			which_4 = 1;
		}
		blendimage('rob_div', 'rob_img', 'rob', rotate_time, which_4);
		//blendimage('dana_div', 'dana_img', 'dana', rotate_time, which_4);
		//blendimage('reed_div', 'reed_img', 'reed',  rotate_time, which_4);
	}
	loop += 1;
	if(loop > 3 )
	{
		loop = 1;
	}
	
	timerID = setTimeout('start()', rotate_time);
}
/**
######################################################################
**/
function blendimage(divid, imageid, imagefolder, rotate_time, count) {
	var speed = Math.round(rotate_time / 150);
	var timer = 0;
	var timer_id = null;
	
	//fade in image
	for(i = 100; i >= 0; i--) {
		timer_id = setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
		timer++;
		if(i == 0)
		{
			clearTimeout(timer_id);
			//switch background to the top image
			imagefile = 'http://www.bethelcollege.edu/blogs/custom/images/home/rotate/'+imagefolder+'/'+count+'.jpg';
			document.getElementById(imageid).src = imagefile;
			//set opac to 100 for image
			changeOpac(100, imageid);
			//set new background
			count++;
			if(count > 4){
				count = 1;
			}
			bg_image = 'http://www.bethelcollege.edu/blogs/custom/images/home/rotate/'+imagefolder+'/'+count+'.jpg';
			document.getElementById(divid).style.background = 
				" url('"+bg_image + "') 5px 5px no-repeat";
		}
	}
}
//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 + ")";
}
/**************************************/

/***************/
window.onload = function () {
	start();
}