var cssPath_small = "css/s.css";
var cssPath_middle = "css/m.css";
var cssPath_large = "css/l.css";

var small_on = "http://www.cmi.co.jp/img/all/font_e_s_on.jpg";
var small_off = "http://www.cmi.co.jp/img/all/font_e_s.jpg";
var middle_on = "http://www.cmi.co.jp/img/all/font_e_m_on.jpg";
var middle_off = "http://www.cmi.co.jp/img/all/font_e_m.jpg";
var large_on = "http://www.cmi.co.jp/img/all/font_e_l_on.jpg";
var large_off = "http://www.cmi.co.jp/img/all/font_e_l.jpg";

window.onload = function(){	
	preloadImg();
	chngFontSize(getCookie());
}

function preloadImg(){
	
	var img01 = new Image();
	var img02 = new Image();
	var img03 = new Image();
	var img04 = new Image();
	var img05 = new Image();
	var img06 = new Image();
	
	img01.src = small_on;
	img02.src = small_off;
	img03.src = middle_on;
	img04.src = middle_off;
	img05.src = large_on;
	img06.src = large_off;
}

function chngFontSize(val){
	
	if(document.getElementsByTagName){
	
		var lnkObj = document.getElementsByTagName("link");
		
		var cssObj_small = getCssObj(lnkObj,cssPath_small);
		var cssObj_middle = getCssObj(lnkObj,cssPath_middle);
		var cssObj_large = getCssObj(lnkObj,cssPath_large);
		
		switch(val){
			case "small":
				cssObj_small.disabled = false;
				cssObj_middle.disabled = true;
				cssObj_large.disabled = true;
				break;
			case "middle":
				cssObj_small.disabled = true;
				cssObj_middle.disabled = false;
				cssObj_large.disabled = true;
				break;
			case "large":
				cssObj_small.disabled = true;
				cssObj_middle.disabled = true;
				cssObj_large.disabled = false;
				break;
			default:
				cssObj_small.disabled = true;
				cssObj_middle.disabled = false;
				cssObj_large.disabled = true;
		}
		
		chngBtnImg(val);
		setCookie(val);
	}
}

function getCssObj(lnkObj,path){
	for(var i = 0; i < lnkObj.length; i++){
		if(lnkObj[i].getAttribute("href").indexOf(path) != -1) break;
	}
	return lnkObj[i];
}

function chngBtnImg(val){
	switch(val){
		case "small":
			document.getElementById("t_small").src = small_on;
			document.getElementById("t_middle").src = middle_off;
			document.getElementById("t_large").src = large_off;
			document.getElementById("t_small").style.cursor = 'default';
			document.getElementById("t_middle").style.cursor = 'pointer';
			document.getElementById("t_large").style.cursor = 'pointer';
			break;
		case "middle":
			document.getElementById("t_small").src = small_off;
			document.getElementById("t_middle").src = middle_on;
			document.getElementById("t_large").src = large_off;
			document.getElementById("t_small").style.cursor = 'pointer';
			document.getElementById("t_middle").style.cursor = 'default';
			document.getElementById("t_large").style.cursor = 'pointer';
			break;
		case "large":
			document.getElementById("t_small").src = small_off;
			document.getElementById("t_middle").src = middle_off;
			document.getElementById("t_large").src = large_on;
			document.getElementById("t_small").style.cursor = 'pointer';
			document.getElementById("t_middle").style.cursor = 'pointer';
			document.getElementById("t_large").style.cursor = 'default';
			break;
		default:
			document.getElementById("t_small").src = small_off;
			document.getElementById("t_middle").src = middle_on;
			document.getElementById("t_large").src = large_off;
			document.getElementById("t_small").style.cursor = 'pointer';
			document.getElementById("t_middle").style.cursor = 'default';
			document.getElementById("t_large").style.cursor = 'pointer';
	}
}

function setCookie(val){
	if(navigator.cookieEnabled){
		var exp = new Date();
		exp.setTime(exp.getTime()+(365*1000*60*60*24));
		exp = exp.toGMTString();
		document.cookie = "fontSize=" + val + ";expires=" + exp + ";path=/;";
	}
}

function getCookie(){
	var key = "fontSize=";
	var r_cookie = document.cookie + ";";
	var st = r_cookie.indexOf(key);
	if(st != -1){
		var ed = r_cookie.indexOf(";",st);
		var ret = r_cookie.substring(st + key.length,ed);  
	}
	return ret;	
}