Minesweeper guess counter

<html>
<head><title>Javascript Minesweeper</title>
<style type="text/css">
.a {
 color: blue;
 text-decoration: underline;
 cursor: pointer }
.y {
 overflow: auto;
 max-width: 800px;
 max-height: 600px;
 text-align: center;
 vertical-align: middle;
}
span#stats {
 font-size: 80%;
}
</style>
<script type="text/javascript">
<!--

var h, w, m; // Height, width, mines in board
var squares = []; // Holds board data - 1,2,4 bits = mine,flag,opened

var patterns =
 [[[3,2], [0,0], [0,1], [0,2], [3,0], [3,1], [3,2], [1,1,2,1]], // linear
  [[2,3], [0,0], [1,0], [2,0], [0,3], [1,3], [2,3], [1,1,1,2]], // linear
  [[6,2], [0,0], [0,1], [0,2], [6,0], [6,1], [6,2], [1,1,2,1], [2,1,4,1],[4,1,5,1]], // double linear
  [[2,6], [0,0], [1,0], [2,0], [0,6], [1,6], [2,6], [1,1,1,2], [1,2,1,4],[1,4,1,5]], // double linear
  [[3,3], [0,0], [3,0], [0,3], [3,3], [1,1,1,2], [1,1,2,1], [1,2,2,2]]]; // block

function initialize() {
 loadBoard(262, 718, 40000);
 var max = 10;
 var z = 0;
 var k = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];
 var total = 0;
 document.getElementById('stats').innerHTML = "";
 for (var q=0; q<max; q++) {
  placeMines();
  var holder = [];
  for (var i=0; i<h+2; i++) {
   holder[i] = [];
   for (var j=0; j<w+2; j++) {
    if (j==0 || j==w+1 || i==0 || i==h+1) holder[i][j] = 1;
    else holder[i][j] = (squares[i-1][j-1] & 1);
   }
  }
  if (countGuesses(holder) >= k.length) {
   for (var i=k.length; i<=countGuesses(holder); i++) {
    k[i] = 0;
   }
  }
  k[countGuesses(holder)]++;
  total += countGuesses(holder);
 }
 document.getElementById('stats').innerHTML += k + "<br>" + (total/max);
}

function loadBoard(newH, newW, newM) {
 h = newH;
 w = newW;
 m = newM;
 for (var i=0; i<h; i++) {
  squares[i] = [];
  for (var j=0; j<w; j++) {
   squares[i][j] = 0;
  }
 }
}

function clearBoard() {
 for (var i=0; i<h; i++) {
  for (var j=0; j<w; j++) {
   squares[i][j] = 0;
  }
 }
}

function placeMines() {
 clearBoard();
 for (var i=0; i<m; i++) {
  var done = false;
  while (!done) {
   var newX = Math.floor(Math.random() * w);
   var newY = Math.floor(Math.random() * h);
   if ((squares[newY][newX] & 1) == 0) {
    squares[newY][newX]++;
    done = true;
   }
  }
 }
}

function printMines() {
 var s="<pre>";
 for (var i=0; i<h; i++) {
  for (var j=0; j<w; j++) {
   s += (squares[i][j]==0 ? "." : "X")
  }
  s += "<br>";
 }
 document.getElementById('stats').innerHTML += s;
}

function countGuesses(arr) {
 var num=0;
  for (var a=0; a<patterns.length; a++) { // a-th pattern
   for (var b=0; b<h+2-patterns[a][0][0]; b++) { // i index
    for (var c=0; c<w+2-patterns[a][0][1]; c++) { // j index
     var good = true;
     for (var d=1; d<patterns[a].length; d++) { // number of the set
      var cnt = 0;
      for (var e=0; 2*e<patterns[a][d].length; e++) { // coordinate pair of the set
       cnt += arr[b+patterns[a][d][2*e]][c+patterns[a][d][2*e+1]];
      }
      if (cnt != 1) good = false;
     }
     //if (good) {num++; document.getElementById('stats').innerHTML += b+"."+c+"<br>";}
     if (good) num++;
    }
   }
  }
 return num;
}

function isMine(x, y) {
 if (isValid(x,y) && (squares[y][x] & 1) > 0) return 1;
 else return 0;
}

function isValid(x, y) {
 if (x < 0 || y < 0 || x >= w || y >= h) return false;
 return true;
}

// -->
</script></head>
<body onload="initialize()" onkeydown="if(event.keyCode==113) resetBoard(false)" bgcolor="#f8f8f8">
<span id="stats">&nbsp;</span>
</body>
</html>