var slideNum = 1;
var slideNextNum = 1;

var slidehTimerStep;
var slidehTimerPict;

var slideSpeed = 3000;
var slideEffectSpeed = 50;

var slidePrefix = 'leftSlide';
var slidePrefix2 = 'rightSlide';

var slideNow;

var isLeft = false;
var slideNumLeft = 1;
var slideNumRight = 1;



var slideEffectStep;

function slideSetOpacity(el, num) {
el.style.opacity = num / 100;
if(el.filters) {el.style.filter ="progid:DXImageTransform.Microsoft.Alpha(opacity=" + num + ")";}
}


//starts current slide chahge
function slideStartChange() {
if(isLeft) {
	isLeft = false;
	slideNow = slidePrefix2;
	slideNum = slideNumRight;
	}
else {
	isLeft = true;
	slideNow = slidePrefix;	
	slideNum = slideNumLeft;
	}
slideEffectStep = 1;
window.setTimeout('slideChangeEffectStep()', slideEffectSpeed);	
}

//makes nother step of slide
function slideChangeEffectStep() {
if(slideEffectStep == 1) {
	if(document.getElementById(slideNow + (slideNum + 1))) {slideNextNum = slideNum + 1;}
	else {slideNextNum = 1;}
	document.getElementById(slideNow + slideNum).style.display = 'block';
	document.getElementById(slideNow + slideNextNum).style.display = 'block';
	slideSetOpacity(document.getElementById(slideNow + slideNum), 100);
	slideSetOpacity(document.getElementById(slideNow + slideNextNum), 0);
		
	document.getElementById(slideNow + slideNum).style.zIndex = 100;
	document.getElementById(slideNow + slideNextNum).style.zIndex = 50;
	}
if(slideEffectStep > 20) {
	document.getElementById(slideNow + slideNum).style.display = 'none';
	if(document.getElementById(slideNow + (slideNum + 1))) {slideNum++;}
	else {slideNum = 1;}
	if(isLeft) {slideNumLeft = slideNum;}
	else {slideNumRight = slideNum;}
	document.getElementById(slideNow + slideNum).style.display = 'block';
	window.setTimeout('slideStartChange()', slideSpeed);
	}
else {
	slideEffectStep++;
	slideSetOpacity(document.getElementById(slideNow + slideNum), 100 - slideEffectStep * 5);
	slideSetOpacity(document.getElementById(slideNow + slideNextNum), slideEffectStep * 5);
	window.setTimeout('slideChangeEffectStep()', slideEffectSpeed);
	}
}

//when all images are loaded starts the slide show
function slideDoSlide() {
window.setTimeout('slideStartChange()', slideSpeed);
}