// Concentration Memory Game with Images - Head Script
// copyright Stephen Chapman, 28th February 2006, 24th December 2009
// you may copy this script provided that you retain the copyright notice

var back = 'back.gif';
var tile = ['img0.gif','img1.gif','img2.gif','img3.gif','img4.gif','img5.gif',
'img6.gif','img7.gif','img8.gif','img9.gif','img10.gif','img11.gif',
'img12.gif','img13.gif','img14.gif'];

function randOrd(a, b){return (Math.round(Math.random())-0.5);} var im = []; for (var i = 0; i < 15; i++) {im[i] = new Image(); im[i].src = tile[i]; tile[i] = '<img src="'+tile[i]+'" width="60" height="60" alt="tile" \/>'; tile[i+15] = tile[i];} function displayBack(i) {document.getElementById('t'+i).innerHTML = '<div onclick="disp('+i+');return false;"><img src="'+back+'" width="60" height="60" alt="back" \/><\/div>';} var ch1, ch2, tmr, tno, tid, cid, cnt; window.onload=start; function start() {for (var i = 0; i <= 29 ;i++) displayBack(i);clearInterval(tid);tmr = tno = cnt = 0;tile.sort( randOrd );cntr(); tid = setInterval('cntr()', 1000);} function cntr() {var min = Math.floor(tmr/60);var sec = tmr%60;document.getElementById('cnt').value = min+':'+ (sec<10 ? '0' : '') + sec;tmr++;} function disp(sel) {if (tno>1) {clearTimeout(cid); conceal();}document.getElementById('t'+sel).innerHTML = tile[sel];if (tno==0) ch1 = sel;else {ch2 = sel;  cid = setTimeout('conceal()', 900);}tno++;} function conceal() {tno = 0; if (tile[ch1] != tile[ch2]) {displayBack(ch1);displayBack(ch2);} else cnt++; if (cnt >= 15) clearInterval(tid);}