function changePictures() {
   user_pic = document.gamer.userpic.value; 
   comp_pic = document.gamer.comppic.value; 
	var x=document.getElementById("userpic")
	userx = x.options[x.selectedIndex].text
	var y=document.getElementById("comppic")
	compx = y.options[y.selectedIndex].text
   message("You can start (you're " + userx + ", I'm " + compx + ") Click on the piece you want to move, then click on the square you want to move it to.");
   history.go()
}

user_pic = document.gamer.userpic.value
comp_pic = document.gamer.comppic.value

var x=document.getElementById("userpic")
userx = x.options[x.selectedIndex].text

var y=document.getElementById("comppic")
compx = y.options[y.selectedIndex].text


// Checkers Game

// lite.gif
// dark.gif
// user1.jpg -- normal piece (player/dark beer)
// user2.jpg -- highlighted piece
// user1k.jpg -- kinged normal piece
// user2k.jpg -- kinged highlighted piece
// comp1.jpg -- normal piece (computer/lite_beer)
// comp2.jpg -- highlighted piece
// comp1k.jpg -- kinged normal piece
// comp2k.jpg -- kinged highlighted piece

var messagex = "You're doing OK, "+ userx + "!"
var messagey = "You're a TOPNOTCH player, "+ userx + "!"

function preload() {
 this.length = preload.arguments.length;
 for (var i = 0; i < this.length; i++) {
  this[i] = new Image();
  this[i].src = preload.arguments[i];
 }
}
var pics = new preload("lite.gif","dark.gif",
 user_pic + "1.jpg", user_pic + "2.jpg", user_pic + "1k.jpg", user_pic + "2k.jpg",
 comp_pic + "1.jpg", comp_pic + "2.jpg", comp_pic + "1k.jpg", comp_pic + "2k.jpg");

function playSound(whSound) { if (window.auCon) auCon.control(whSound,true); }
function stopSound(whSound) { if (window.auCon) auCon.control(whSound,false); }

var lite = -1; // computer is light beer
var red = 1; // visitor is dark beer
var square_dim = 45;
var piece_toggled = false;
var my_turn = false;
var double_jump = false;
var comp_move = false;
var game_is_over = false;
var safe_from = safe_to = null;
var toggler = null;
var togglers = 0;
var moves = 0;
window.status = "Move counter = " + moves
function Board() {
 board = new Array();
 for (var i=0;i<8; i++) {
  board[i] = new Array();
  for (var j=0;j<8;j++)
   board[i][j] = Board.arguments[8*j+i];
 }
 board[-2] = new Array(); // prevents errors
 board[-1] = new Array(); // prevents errors
 board[8] = new Array(); // prevents errors
 board[9] = new Array(); // prevents errors
}
var board;
Board(1,0,1,0,1,0,1,0,
      0,1,0,1,0,1,0,1,
      1,0,1,0,1,0,1,0,
      0,0,0,0,0,0,0,0,
      0,0,0,0,0,0,0,0,
      0,-1,0,-1,0,-1,0,-1,
      -1,0,-1,0,-1,0,-1,0,
      0,-1,0,-1,0,-1,0,-1);

function message(str) {
 if (!game_is_over)
  document.disp.message.value = str;
}
function moveable_space(i,j) {
 // calculates whether it is a dark (moveable)
 // or lite (non-moveable) space
 return (((i%2)+j)%2 == 0);
}
function Coord(x,y) {
 this.x = x;
 this.y = y;
}
function coord(x,y) {
 c = new Coord(x,y);
 return c;
}

document.write("<table border=0 cellspacing=0 cellpadding=0 width="+(square_dim*8+8)
 +"<tr><td><img src='lite.gif' width="+(square_dim*8+8)
 +" height=4><br></td></tr>");
for(var j=0;j<8;j++) {
 document.write("<tr><td><img src='lite.gif' width=4 height="+square_dim+">");
 for(var i=0;i<8;i++) {
  if (moveable_space(i,j))
   document.write("<a href='javascript:clicked("+i+","+j+")'>");
  document.write("<img src='");
  if (board[i][j]==1) document.write(user_pic+"1.jpg");
  else if (board[i][j]==-1) document.write(comp_pic+"1.jpg");
  else if (moveable_space(i,j)) document.write("dark.gif");
  else document.write("lite.gif");
  document.write("' width="+square_dim+" height="+square_dim
   +" name='space"+i+""+j+"' border=0>");
  if (moveable_space(i,j)) document.write("</a>");
 }
 document.write("<img src='lite.gif' width=4 height="+square_dim+"></td></tr>");
}
document.write("<tr><td><img src='lite.gif' width="+(square_dim*8+8)
 +" height=4><br></td></tr></table><br>"
 +"<form name='disp'><textarea name='message' wrap=virtual rows=4 cols=50></textarea><br><input "
 +"type=button value=\"Set-em Up!!!\" onClick=\"location.href+=''\"></form>");

function clicked(i,j) {
 if (my_turn) {
  if (integ(board[i][j])==1) toggle(i,j);
  else if (piece_toggled) move(selected,coord(i,j));
  else message("First click one of your " + userx + " pieces, then click where you want to move it.");
 } else {
  message("It's not your turn yet. Have a shot while you're waiting!");
 }
}
function toggle(x,y) {
 if (my_turn) {
  if (piece_toggled)
   draw(selected.x,selected.y,user_pic+"1"+((board[selected.x][selected.y]==1.1)?"k":"")+".jpg");
  if (piece_toggled && (selected.x == x) && (selected.y == y)) {
   piece_toggled = false;
   if (double_jump) { my_turn = double_jump = false; computer(); }
  } else {
   piece_toggled = true;
   draw(x,y,user_pic+"2"+((board[x][y]==1.1)?"k":"")+".jpg");
  }
  selected = coord(x,y);
 } else {
  if ((piece_toggled) && (integ(board[selected_c.x][selected_c.y])==-1))
   draw(selected_c.x,selected_c.y,comp_pic+"1"+((board[selected_c.x][selected_c.y]==-1.1)?"k":"")+".jpg");
  if (piece_toggled && (selected_c.x == x) && (selected_c.y == y)) {
   piece_toggled = false;
  } else {
   piece_toggled = true;
   draw(x,y,comp_pic+"2"+((board[x][y]==-1.1)?"k":"")+".jpg");
  }
  selected_c = coord(x,y);
 }
}
function draw(x,y,name) {
 document.images["space"+x+""+y].src = name;
  window.status = "Move counter = " + moves
}
function integ(num) {
 if (num != null)
  return Math.round(num);
 else
  return null;
}
function abs(num) {
 return Math.abs(num);
}
function sign(num) {
 if (num < 0) return -1;
 else return 1;
}
function concatenate(arr1,arr2) {
 // function tacks the second array onto the end of the first and returns result
 for(var i=0;i<arr2.length;i++)
  arr1[arr1.length+i] = arr2[i];
 return arr1;
}
function legal_move(from,to) {
 if ((to.x < 0) || (to.y < 0) || (to.x > 7) || (to.y > 7)) return false;
 piece = board[from.x][from.y];
 distance = coord(to.x-from.x,to.y-from.y);
 if ((distance.x == 0) || (distance.y == 0)) {
  message("You may only move diagonally.");
  return false;
 }
 if (abs(distance.x) != abs(distance.y)) {
  message("Invalid move.");
  return false;
 }
 if (abs(distance.x) > 2) {
  message("Invalid move.");
  return false;
 }
 if ((abs(distance.x) == 1) && double_jump) {
  return false;
 }
 if ((board[to.x][to.y] != 0) || (piece == 0)) {
  return false;
 }
 if ((abs(distance.x) == 2)
 && (integ(piece) != -integ(board[from.x+sign(distance.x)][from.y+sign(distance.y)]))) {
  return false;
 }
 if ((integ(piece) == piece) && (sign(piece) != sign(distance.y))) {
  return false;
 }
 
 return true;
}
function move(from,to) {
 my_turn = true;
 if (legal_move(from,to)) {
  moves = moves + 1
  piece = board[from.x][from.y];
  distance = coord(to.x-from.x,to.y-from.y);
  if ((abs(distance.x) == 1) && (board[to.x][to.y] == 0)) {
   swap(from,to);
  } else if ((abs(distance.x) == 2)
  && (integ(piece) != integ(board[from.x+sign(distance.x)][from.y+sign(distance.y)]))) {
   double_jump = false;
   swap(from,to);
   remove(from.x+sign(distance.x),from.y+sign(distance.y));
   if ((legal_move(to,coord(to.x+2,to.y+2)))
   || (legal_move(to,coord(to.x+2,to.y-2)))
   || (legal_move(to,coord(to.x-2,to.y-2)))
   || (legal_move(to,coord(to.x-2,to.y+2)))) {
    double_jump = true;
    message("You may complete the double jump or click on your piece to stay still.");
   }
  }
    if (moves > 6) { 
      messagex = "You might have a chance to break the record (13 moves)!" 
      messagey = "You're an EXPERT player!"}
  if (moves > 13) { 
      messagex = "You didn't break the record!"
      messagey = "You're a GREAT player!"}
  if (moves > 32) { 
      messagex = "You're a good player, hang in there!          [Click on an ad, maybe I'll give you a chance!]"   
      messagey = "You're a GOOD player!"}
  if (moves > 37) { 
      messagex = "C'mon, play it out!          [I'll let you win if you click on one of the ads!]]"
      messagey = "You're an OK player!"}
  if (moves > 42) { 
      messagex = "You'd better hope you don't lose to a computer!          [If you really want to win, click on one of the ads!]"
      messagey = "You're not a very good player - now go visit the advertisers!"}
  if (moves > 47) { 
      messagex = "You ready to quit yet?           [I guess you didn't click on the right ad!]" 
      messagey = "You're a pretty lousy player - keep trying, after you visit the advertisers!"}
  if (moves > 52) { 
      messagex = "My grandmother can play better than you!     [this space available for advertising]"
      messagey = "Keep trying, you can't do much worse! But first, visit the advertisers!"}
  if (moves > 64) { 
      messagex = "You SUCK !" 
      messagey = "Maybe should you take up another sport after you visit the advertisers!"}
  if (moves > 76) { 
      messagex = "You really SUCK !" 
      messagey = "PLEASE take up another sport after you visit the advertisers!"}
  if (moves > 88) { 
      messagex = "You really, really SUCK !" 
      messagey = "Time to get a CHECKERS STRATEGY BOOK after you visit the advertisers!"}
  if (moves > 100) { 
      messagex = "You really really really SUCK !" 
      messagey = "After visiting the advertisers, read CHECKERS FOR DUMMIES!"}
  if (moves > 112) { 
      messagex = "I'm laughing too hard, I'm not sure if I can take much more of this!" 
      messagey = "My stomach hurts from laughing at you!  Maybe you should just visit the advertisers!"}
  if (moves > 124) { 
      messagex = "C'mon, start over, I can't take it!"
      messagey = "I won't tell anyone how badly you did, if you visit the advertisers!"}

  if ((board[to.x][to.y] == 1) && (to.y == 7)) king_me(to.x,to.y);
  selected = to;
  if (game_over() && !double_jump) {
   setTimeout("toggle("+to.x+","+to.y+");my_turn = double_jump = false;computer();",1000);
  }
 }
 return true;
}
function king_me(x,y) {
 if (board[x][y] == 1) {
  board[x][y] = 1.1; // king you
  draw(x,y,user_pic+"2k.jpg");
 } else if (board[x][y] == -1) {
  board[x][y] = -1.1; // king me
  draw(x,y,comp_pic+"2k.jpg");
 }
}

function swap(from,to) {
 if (my_turn || comp_move) {
  dummy_src = document.images["space"+to.x+""+to.y].src;
  document.images["space"+to.x+""+to.y].src = document.images["space"+from.x+""+from.y].src;
  document.images["space"+from.x+""+from.y].src = dummy_src;
 }
 dummy_num = board[from.x][from.y];
 board[from.x][from.y] = board[to.x][to.y];
 board[to.x][to.y] = dummy_num;
}
function remove(x,y) {
 if (my_turn || comp_move)
  draw(x,y,"dark.gif");
 board[x][y] = 0;
}
function Result(val) {
 this.high = val;
 this.dir = new Array();
}
function move_comp(from,to) {
 toggle(from.x,from.y);
 comp_move = true;
 swap(from,to);
 if (abs(from.x-to.x) == 2) {
  remove(from.x+sign(to.x-from.x),from.y+sign(to.y-from.y));
 }
 if ((board[to.x][to.y] == -1) && (to.y == 0)) king_me(to.x,to.y);
 setTimeout("selected_c = coord("+to.x+","+to.y+");piece_toggled = true;",900);
 setTimeout("bak=my_turn;my_turn=false;toggle("+to.x+","+to.y+");my_turn=bak;",1000);
 if (game_over()) {
  setTimeout("comp_move = false;my_turn = true;togglers=0;",600);
  message("Ok. It's your turn. You may make your move.      "+ moves + " moves so far! " + messagex );
 }
 return true;
}
function game_over() { // make sure game is not over (return false if game is over)
 comp = you = false;
 for(var i=0;i<8;i++) {
  for(var j=0;j<8;j++) {
   if(integ(board[i][j]) == -1) comp = true;
   if(integ(board[i][j]) == 1) you = true;
  }
 }
 if (!comp) message(userx + " beat " + compx + " in " + moves + " moves!  " + messagey + "  While I finish the remaining drinks, use discount code IWON, or go to http://www.beercheckers.com/iwon.html for your discount.");
 if (!you) message(compx + " beat " + userx + " in " + moves + " moves! Game over.  " + messagey + "  You finish ALL the remaining drinks!!!!   Now would be a good time to BUY A GAME!!!!");
 game_is_over = (!comp || !you)
 return (!game_is_over);
}

// the higher the jump_priority, the more often the computer will take the jump over the safe move
var jump_priority = 10;

function computer() {
 // step one - prevent any jumps
 for(var j=0;j<8;j++) {
  for(var i=0;i<8;i++) {
   if (integ(board[i][j]) == 1) {
    if ((legal_move(coord(i,j),coord(i+2,j+2))) && (prevent(coord(i+2,j+2),coord(i+1,j+1)))) {
     return true;
    } if ((legal_move(coord(i,j),coord(i-2,j+2))) && (prevent(coord(i-2,j+2),coord(i-1,j+1)))) {
     return true;
    }
   } if (board[i][j] == 1.1) {
    if ((legal_move(coord(i,j),coord(i-2,j-2))) && (prevent(coord(i-2,j-2),coord(i-1,j-1)))) {
     return true;
    } if ((legal_move(coord(i,j),coord(i+2,j-2))) && (prevent(coord(i+2,j-2),coord(i+1,j-1)))) {
     return true;
    }
   }
  }
 }
 // step two - if step one not taken, look for jumps
 for(var j=7;j>=0;j--) {
  for(var i=0;i<8;i++) {
   if (jump(i,j))
    return true;
  }
 }
 safe_from = null;
 // step three - if step two not taken, look for safe single space moves
 for(var j=0;j<8;j++) {
  for(var i=0;i<8;i++) {
   if (single(i,j))
    return true;
  }
 }
 // if no safe moves, just take whatever you can get
 if (safe_from != null) {
  move_comp(safe_from,safe_to);
 } else {
  message(userx + " beat " + compx + " in " + moves + " moves!  " + messagey + "  While I finish the remaining drinks, use discount code IWON, or go to http://www.beercheckers.com/iwon.html for your discount.");
  game_is_over = true;
 }
 safe_from = safe_to = null;
 return false;
}
function jump(i,j) {
 if (board[i][j] == -1.1) {  
  if (legal_move(coord(i,j),coord(i+2,j+2))) {
   move_comp(coord(i,j),coord(i+2,j+2));
   setTimeout("jump("+(i+2)+","+(j+2)+");",500);
   return true;
  } if (legal_move(coord(i,j),coord(i-2,j+2))) {
   move_comp(coord(i,j),coord(i-2,j+2));
   setTimeout("jump("+(i-2)+","+(j+2)+");",500);
   return true;
  }
 } if (integ(board[i][j]) == -1) {
  if (legal_move(coord(i,j),coord(i-2,j-2))) {
   move_comp(coord(i,j),coord(i-2,j-2));
   setTimeout("jump("+(i-2)+","+(j-2)+");",500);
   return true;
  } if (legal_move(coord(i,j),coord(i+2,j-2))) {
   move_comp(coord(i,j),coord(i+2,j-2));
   setTimeout("jump("+(i+2)+","+(j-2)+");",500);
   return true;
  }
 }
 return false;
}
function single(i,j) {
 if (board[i][j] == -1.1) {
  if (legal_move(coord(i,j),coord(i+1,j+1))) {
   safe_from = coord(i,j);
   safe_to = coord(i+1,j+1);
   if (wise(coord(i,j),coord(i+1,j+1))) {
    move_comp(coord(i,j),coord(i+1,j+1));
    return true;
   }
  } if (legal_move(coord(i,j),coord(i-1,j+1))) {
   safe_from = coord(i,j);
   safe_to = coord(i-1,j+1);
   if (wise(coord(i,j),coord(i-1,j+1))) {
    move_comp(coord(i,j),coord(i-1,j+1));
    return true;
   }
  }
 } if (integ(board[i][j]) == -1) {
  if (legal_move(coord(i,j),coord(i+1,j-1))) {
   safe_from = coord(i,j);
   safe_to = coord(i+1,j-1);
   if (wise(coord(i,j),coord(i+1,j-1))) {
    move_comp(coord(i,j),coord(i+1,j-1));
    return true;
   }
  } if (legal_move(coord(i,j),coord(i-1,j-1))) {
   safe_from = coord(i,j);
   safe_to = coord(i-1,j-1);
   if (wise(coord(i,j),coord(i-1,j-1))) {
    move_comp(coord(i,j),coord(i-1,j-1));
    return true;
   }
  }
 }
 return false;
}
function possibilities(x,y) {
 if (!jump(x,y))
  if (!single(x,y))
   return true;
  else
   return false;
 else
  return false;
}
function prevent(end,s) {
 i = end.x;
 j = end.y;
 if (!possibilities(s.x,s.y))
  return true;
 else if ((integ(board[i-1][j+1])==-1) && (legal_move(coord(i-1,j+1),coord(i,j)))) {
   return move_comp(coord(i-1,j+1),coord(i,j));
 } else if ((integ(board[i+1][j+1])==-1) && (legal_move(coord(i+1,j+1),coord(i,j)))) {
   return move_comp(coord(i+1,j+1),coord(i,j));
 } else if ((board[i-1][j-1]==-1.1) && (legal_move(coord(i-1,j-1),coord(i,j)))) {
   return move_comp(coord(i-1,j-1),coord(i,j));
 } else if ((board[i+1][j-1]==-1.1) && (legal_move(coord(i+1,j-1),coord(i,j)))) {
   return move_comp(coord(i+1,j-1),coord(i,j));
 } else {
  return false;
 }
}
function wise(from,to) {
 i = to.x;
 j = to.y;
 n = (j>0);
 s = (j<7);
 e = (i<7);
 w = (i>0);
 if (n&&e) ne = board[i+1][j-1]; else ne = null;
 if (n&&w) nw = board[i-1][j-1]; else nw = null;
 if (s&&e) se = board[i+1][j+1]; else se = null;
 if (s&&w) sw = board[i-1][j+1]; else sw = null;
 eval(((j-from.y != 1)?"s":"n")+((i-from.x != 1)?"e":"w")+"=0;");
 if ((sw==0) && (integ(ne)==1)) return false;
 if ((se==0) && (integ(nw)==1)) return false;
 if ((nw==0) && (se==1.1)) return false;
 if ((ne==0) && (sw==1.1)) return false;
 return true;
}
  
message("You can start (you're " + userx + ", I'm " + compx + ") Click on the piece you want to move, then click on the square you want to move it to.");
my_turn = true;