// JavaScript Document

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--) {
			var t = setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	} else if(opacStart < opacEnd) {
		for(i = opacStart; i <= opacEnd; i++)
			{
			var t = 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 loadXMLDoc(url)
{
    xmlhttp=null;
    // code for Mozilla, etc.
    if (window.XMLHttpRequest)
    {
        xmlhttp=new XMLHttpRequest()
    }
    // code for IE
    else if (window.ActiveXObject)
    {
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")
    }
    if (xmlhttp!=null)
    {
        xmlhttp.open("GET",url,true);
        xmlhttp.onreadystatechange=state_Change;
        xmlhttp.send("");
    }
    else
    {
        alert("Your browser does not support XMLHTTP.")
    }
}

function state_Change()
{
    // if xmlhttp shows "loaded"
    if (xmlhttp.readyState==4)
    {
        // if "OK"
        if (xmlhttp.status==200)
        {   
            document.images.fadingpic.src='';                    
            document.images.fadingpic.src=xmlhttp.responseText;
        }
        else
        {
            alert("Problem retrieving data:" + xmlhttp.statusText)
        }
    }
}

function imgTick()
{
    changeOpac(0,'fader'); 
    //document.images.fadingpic.src='';
    var url = 'kuvaloop/images.php';
    loadXMLDoc(url);
    shiftOpacity('fader',1000);
    setTimeout('imgTick()',9000);
}