// JavaScript Document
//透明度設定
//filter:alpha(opacity=50);  Internet Explorer 0～100 （整数）
//-moz-opacity: 0.5;  Firefox 0～1.0 （小数）
//opacity:0.5;  Safari 0～1.0 （小数）





var crrentBlock="main0";
var opacityValue=1;
var step=0.01;
var timer;



//フェード開始用
function fadeStart(block){
	if(!timer){
		timer=setInterval("fadeout('"+block+"')",1);
	}
}


function fadeout(block){
	if(opacityValue>=0.05){
		opacityValue -= step;
	}else{
		opacityValue = 0;
		clearInterval(timer);
		document.getElementById(crrentBlock).style.display = "none";
		crrentBlock = block;
		document.getElementById(crrentBlock).style.display = "block";
		timer = setInterval("fadein()",1);
	}
	blockOpacity();
}

//フェードイン
function fadein(){
	if(opacityValue<=1){
		opacityValue+=step;
	}else{
		opacityValue=1;
		clearInterval(timer);
		timer = undefined;
	}
	blockOpacity();
}

//透明度を設定
function blockOpacity(){
	document.getElementById(crrentBlock).style.opacity = opacityValue;//safari
	document.getElementById(crrentBlock).style.MozOpacity = opacityValue;
	
	var ieAl ="alpha(opacity="+(opacityValue * 100)+")";

	document.getElementById(crrentBlock).style.filter = ieAl;
	
}