var opacity = 1;
var increase = 0;
var decrease = 1;
var intervalID = null;
var image = null;
var is_loaded = true;
var str;
var is_downloaded = false;
	

var main_w=0;
var main_h=0;
var res_w=0;

function fade()
{	
	if(increase && is_downloaded){
		if (opacity < 1 && increase){
		  opacity+=0.1;
		}
		else{	
		  if(is_downloaded) is_loaded = true;
		  clearInterval(intervalID);
		}
	}
	if(decrease){
		if (opacity > 0 && decrease){
		  opacity-=0.1;
		}
		else{
			increase=1;
			decrease=0;			
			document.getElementById('img_main').src = str.src;
			if(screen.width > 1024) res_w = 420; else res_w = 320;
			document.getElementById('img_main').style.marginTop=(res_w - main_h)/2;
			document.getElementById('main_img_link').href=str.src;
			resizemain();
		}
	}
	setMainImage();
}

function setMainImage()
{
	document.getElementById('img_main').style.opacity=opacity;
	document.getElementById('img_main').style.filter = "alpha(opacity=" + opacity*100 + ")";	
}

function resizemain()
{	
	document.getElementById('img_main').width = main_w;
	document.getElementById('img_main').height = main_h;
}
function StartFade(img,w,h)
{
	if(is_loaded)
	{		
		is_loaded=false;
		opacity = 1;
	    increase = 0;
	    decrease = 1;	
		str = img;
		main_w = w;
		main_h = h;
		intervalID = setInterval("fade()",10);
	}
}


function downloaded()
{
	is_downloaded = true;
}

function fade_in_tab(obj)
{
	obj.style.opacity=1;
	obj.style.filter = "alpha(opacity=100)";
}

function fade_out_tab(obj)
{
	obj.style.opacity=0.5;
	obj.style.filter = "alpha(opacity=50)";
}

function setOpacity()
{
    var i1 = document.getElementById('trumb1');
	var i2 = document.getElementById('trumb2');
	var i3 = document.getElementById('trumb3');
	var i4 = document.getElementById('trumb4');
	
	fade_out_tab(i1);
	fade_out_tab(i2);
	fade_out_tab(i3);
	fade_out_tab(i4);
}