// JavaScript Document
var del;
var aboutFlag = false;
var mainFlag = true;
var chronicleFlag = true;
var linkFlag = true;

function setOpacity(content1, content2,level){
		var standard = level/10;
		var ie = level*10;
		content1.style.opacity = standard;
		content1.style.filter = "alpha(opacity="+ie+")"	;	
		content2.style.opacity = standard;
		content2.style.filter = "alpha(opacity="+ie+")"; 

}

function getFlag(item){
	switch(item){
		
		case 'about':
			return aboutFlag;
			break;
		case 'main':
			return mainFlag;
			break;
		case 'chronicle':
			return chronicleFlag;		
			break;
		case 'link':
			return linkFlag;
			break;
	}
}

function showText(fa, en, item){
	enCon = document.getElementById('en_content');
	faCon = document.getElementById('fa_content');

	if(getFlag(item)){	
		setOpacity(faCon, enCon, 0);
		
		faCon.innerHTML = fa;
		enCon.innerHTML = en;
		
		window.clearTimeout(del);
	
		fadeText(faCon, enCon);
	}
	
	switch(item){
		case 'about':
			aboutFlag = false;
			mainFlag = true;
			chronicleFlag = true;
			linkFlag = true;
			break;
		case 'main':
			aboutFlag = true;
			mainFlag = false;
			chronicleFlag = true;
			linkFlag = true;			
			break;
		case 'chronicle':
			aboutFlag = true;
			mainFlag = true;
			chronicleFlag = false;
			linkFlag = true;		
			break;
		case 'link':
			aboutFlag = true;
			mainFlag = true;
			chronicleFlag = true;
			linkFlag = false;
			break;
	}

}

function fadeText(con1, con2){
	current = con1.style.opacity;
	current = current * 10;
	current += 1;
	setOpacity(con1, con2, current);
	if(current < 100){
		del = window.setTimeout(function(){fadeText(con1,con2)},100);
	}
}