/*  AORJA.COM JavaScript home.js ver.1.3 pr1 2010/02/17 
 *  (c)2010  AOR, LTD.
 *
 * <<<< 20s version >>>>
 * The value of selectedClass is ...
 * add 1 every 20 sec
 * add 7 after 5 sec, add 14 after 10 sec, add 21 after 15 sec if reload manually.
 * In chkCnt() function, reload the page at the time of reached +1 value, normally 20 sec later.
 * 
 * eg.  sec |0  5  10 15|20 25 30 35|40 45 50 55|0..
 *    ------+--+--+--+--+--+--+--+--+--+--+--+--+--
 *    value |0  7  14 21|1  8  15 22|3  9  16 23|4..
 *   
 * Therefore every 20 sec, is in series 0, 1, 2,...
 * if reload after  5 sec, is in series 7, 8, 9,...
 * 
 *--------------------------------------------------------------------------*/

var selectedClass;
window.onload=function selItem() {
var bodyClass = ["show01", "show02", "show03", "show04", "show05", "show06", "show07", "show08", "show09", "show10", "show11", "show12", "show13", "show14", "show15", "show16", "show17", "show18", "show19", "show20", "show21", "show22", "show23", "show24", "show25", "show26", "show27", "show28", "show29", "show30", "show01"];
	selectedClass = getCnt();
	document.body.className = bodyClass[selectedClass];
	document.getElementById("showClass").value = selectedClass + 1;
	startChk();
	
};

function getCnt() {
var today = new Date();
var ms = today.getTime();
var cntIntSec = Math.floor(ms/20000);
/* main counter: count up every 20 sec */

var cntShift = 7 * Math.floor(ms/5000 % 4);
/* shift value: add 7 each 5 sec, value 0, 7, 14, 21 */

var	cnt = Math.floor((cntIntSec + cntShift) % 30);	/* upper limit of counter, then renge 0..29 */
	return cnt;
};

function chkCnt() {
var curCnt = getCnt();
	if((curCnt - selectedClass == 1 ) || (curCnt + 30 - selectedClass == 1 )) {
		location.reload();
	}
};

/* cheking interval */
var intTime = 1600;	/* check every 1.6 sec */
var chkTimer;
function startChk() {
	stopChk();
	chkTimer = setInterval("chkCnt()",intTime);
};

function stopChk() {
	clearInterval(chkTimer);
};

/* yyyy/mm/dd of last update
 * --------------------------------------------------------------------------*/

function lastUpdate() {
myModify = document.lastModified;
myD = new Date(myModify);
myYear = myD.getYear();
myYear4 = (myYear < 2000) ? myYear+1900 : myYear;
myMonth = myD.getMonth() + 1;
myDate = myD.getDate();
myStr = myYear4 + "/" + myMonth + "/" + myDate;
return myStr;
}

/*--------------------------------------------------------------------------*/