// Author: Andy Asberry
	// CS316 Program 3: program to simulate the game of Craps
	// October 2007
	
	var age;				// variable for age of user
	var bet;				// variable for the current bet
	var MAXbet;				// variable for the maximum bet of the user
	var stake;				// variable for the current stake
	var MAXstake;			// variable for the maximum stake that the user reached
	var MINstake;			// variable for the minimum stake that the user fell to
	var die1;				// variable for the first die
	var die2;				// variable for the second die
	var sum;				// variable for the sum of the dice
	var numGames;			// variable for the number of games
	var point;				// variable for the point
	var numRolls;			// variable for the number of rolls
	var originalBet;		// variable for the original bet if double on loss functionality is applied
	var firstOriginalBet;	// variable with boolean value whether or not the current bet is the original bet before doubling on loss
	var ifdouble;			// variable with boolean value whether or not the double on loss feature is turned on or off
	
	var MAXnumGames = 2000;	// variable for the maximum number of games that can be played
	var MAX_BET = 1000;		// variable for the maximum bet that can be used
	
	// init function to initialize all necessary variables and text fields to their respective start states
	function init()
	{
		bet = 1;			// Initially, the current bet is set to 1
		MAXbet = 0;			// initially, the maximum bet is set to 0
		MAXstake = 0;		// initially, the maximum stake is set to 0
		MINstake = 0;		// initially, the minimum stake is set to 0
		stake = 0;			// initially, the current stake is set to 0
		die1 = 0;			// initially, the first die is set to 0. If it remains 0, there must have been some error since a die is 1-6
		die2 = 0;			// initially, the second die is set to 0. If it remains 0, there must have been some error  "    "  "  "  "
		sum = 0;			// initially, the sum of the dice is set to 0
		point = 0;			// initially, the point is set to 0
		numGames = 1000;	// initially, the number of games for the run simulation functionality is 1000
		numRolls = 0;		// initially, the number of dice rolls is zero since the dice have not yet been rolled
		originalBet = 1;	// initially, since the initial bet is 1, the initial original bet is set to 1 also
		firstOriginalBet = true;	// initially, this flag is set to true since it is not yet the second bet
		ifdouble = false;			// initially, this flag is set to false since the double on loss button has not yet been clicked
		
		document.getElementById('bet').value = bet;				// set the bet display with the value of the variable bet (1)
		document.getElementById('stake').value = '';			// set the stake display with blank contents
		document.getElementById('minstake').value = MINstake;	// set the minimum stake display with the value being the value of variable MINstake (0)
		document.getElementById('maxstake').value = MAXstake;	// set the maximum stake display with the value being the value of variable MAXstake (0)
		document.getElementById('maxbet').value = MAXbet;		// set the maximum bet display with the value being the value of variable MAXbet (0)
		document.getElementById('die1').value = '';				// set the die 1 display with blank contents
		document.getElementById('die2').value = '';				// set the die 2 display with blank contents
		document.getElementById('sum').value = '';				// set the sum display with blank contents
		document.getElementById('double').value = '';			// set the double on loss display with blank contents
		document.getElementById('winstatus').value = '';		// set the win/loss status display with blank contents
	}
	
	// function to simulate rolling dice, and determining win/loss status. this function also updates the corresponding displays (MAXbet, MAXstake, etc) as it goes
	function rollDice()
	{
		numRolls++;											// increment the number of rolls since the dice have just been rolled
		bet = document.getElementById('bet').value;			// set the value of the bet variable equal to the contents from the bet display
		die1 = Math.floor(Math.random()* (6 + 1));			// set the value of the die1 variable to some random number between 0 and 6 inclusively
		// while the random number for die1 is 0,
		while (die1 == 0)
		{
			die1 = Math.floor(Math.random()* (6 + 1)); 		// we need a number between 1 and 6 inclusively since a die does not have a side with 0 dots
		}
		die2 = Math.floor(Math.random()* (6 + 1));			// set the value of the die2 variable to some random number between 0 and 6 inclusively
		// while the random number for die2 is 0,
		while (die2 == 0)
		{
			die2 = Math.floor(Math.random()* (6 + 1));		// we need a number between 1 and 6 inclusively since a die does not have a side with 0 dots
		}
		document.getElementById('die1').value = die1;		// set the die1 display to the value of the die1 variable
		document.getElementById('die2').value = die2;		// set the die2 display to the value of the die2 variable
		sum = parseInt(die1,10) + parseInt(die2,10);		// set the value of the sum variable to the value of die1 variable plus the value of the die2 variable
		document.getElementById('sum').value = sum;			// set the sum display to the value of the sum variable
		
		// if the current bet is larger than the maximum bet made so far
		if (bet > MAXbet)
		{
			MAXbet = bet;										// make the current bet the maximum bet
			document.getElementById('maxbet').value = MAXbet;	// then change the maxbet display to the value of the MAXbet variable
		}
		
		// if the current roll is the first roll in this round
		if (numRolls == 1)
		{
			// if the sum of the dice is 7 or 11
			if (sum == 7 || sum == 11)
			{
				document.getElementById('winstatus').value = 'You win!';	// change the win/loss status display to win status
				stake = parseInt(stake,10) + parseInt(bet,10);				// add the current bet to the current stake
				document.getElementById('stake').value = stake;				// set the stake display
				// if the double on loss option has been enabled
				if (ifdouble == true)
				{
					if (firstOriginalBet == false)
					{
						bet = parseInt(originalBet,10);						// the bet is equal to the original bet made at the beginning of the double on loss
						document.getElementById('bet').value = bet;			// set the bet display back to the original bet
						firstOriginalBet = true;							// the loss sequence has been broken so reset it
					}
				}
				// if the current stake is larger than the previous maximum stake
				if (stake > MAXstake)
				{
					MAXstake = parseInt(stake,10);							// then set the maximum stake equal to the current stake
					document.getElementById('maxstake').value = MAXstake;	// set the maximum stake display to the value of the maximum stake variable
				}
				numRolls = 0;												// the round has been rolled, so the number of rolls is reset to 0 for the next round
			}
			// else if the sum of the dice is 2, 3, or 12
			else if (sum == 2 || sum == 3 || sum == 12)
			{
				document.getElementById('winstatus').value = 'You lose.';	// set the win/loss status display
				stake = parseInt(stake,10) - parseInt(bet,10);				// subtract the bet from the stake
				document.getElementById('stake').value = stake;				// set the stake display with the value of the stake variable
				// if the current stake is less than the current minimum stake
				if (stake < MINstake)
				{
					MINstake = parseInt(stake,10);							// set the minimum stake variable to the current stake
					document.getElementById('minstake').value = MINstake;	// set the minimum stake display to the value of the minimum stake variable
				}
				// if the double on loss option is enabled
				if (ifdouble == true)
				{
					// if it is the first loss in the loss sequence
					if (firstOriginalBet == true)
					{
						bet = document.getElementById('bet').value;			// set the bet to the value of the bet dispay
						originalBet = parseInt(bet,10);						// set the original bet to the value of the bet variable
						firstOriginalBet = false;							// it is no longer the first loss in the loss sequence
					}
					bet = 2*parseInt(bet,10);								// double the bet
					document.getElementById('bet').value = bet;				// set the bet display
					// if the current bet is larger than the current maximum bet
					if (bet > MAXbet)
					{
						MAXbet = parseInt(bet,10);							// set the maximum bet variable to the current bet
						document.getElementById('maxbet').value = MAXbet;	// set the maximum bet display
					}
				}
				numRolls = 0;												// reset the number of rolls to 0 since the user lost.
			}
			// else the sum is made to be the point for this round
			else
			{
				point = parseInt(sum,10);									// set the point variable to the value of the sum
				document.getElementById('winstatus').value = 'Roll again to make ' + point;	// set the win/loss staus display to roll again to make the point
				numRolls++;													// increment the number of rolls
			}
		}
		// else it is not the first roll in this round and the rules differ slightly
		else
		{
			// if the sum of the dice is 7
			if (sum == 7)
			{
				document.getElementById('winstatus').value = 'You lose.';			// the user loses, set the win/loss status display
				stake = parseInt(stake,10) - parseInt(bet,10);						// subtract the bet from the current stake
				// if the double on loss option has been enabled
				if (ifdouble == true)
				{
					// if it is the first loss in the loss sequence
					if (firstOriginalBet == true)
					{
						bet = document.getElementById('bet').value;					// set the value of the bet variable to the value of the bet display
						originalBet = parseInt(bet,10);								// set the value of the original bet to the current bet
						firstOriginalBet = false;									// it is no longer the first loss in the loss sequence
					}
					bet = 2*parseInt(bet,10);										// double the current bet
					document.getElementById('bet').value = bet;						// set the value of the bet display to the value of the bet variable
					// if the current bet is larger than the current maximum bet
					if (bet > MAXbet)
					{
						MAXbet = parseInt(bet,10);									// set the maximum bet variable to the value of the bet variable
						document.getElementById('maxbet').value = MAXbet;			// set the value of the maximum bet display to the value of the maximum bet variable
					}
				}
				document.getElementById('stake').value = stake;						// set the stake display to the current value of the stake variable
				// if the current stake is less than the minimum stake
				if (stake < MINstake)
				{
					MINstake = parseInt(stake,10);							// set the value of the minimum stake variable to the value of the current stake
					document.getElementById('minstake').value = MINstake;	// set the minimum stake display to the value of the minimum stake variable
				}
				numRolls = 0;												// reset the number of rolls to 0
			}
			// else if the sum of the dice is equal to the point
			else if (sum == point)
			{
				document.getElementById('winstatus').value = 'You win!';	// set the win/loss status display to the win message
				stake = parseInt(stake,10) + parseInt(bet,10);				// add the bet to the current stake
				document.getElementById('stake').value = stake;				// set the stake display to the value of the current stake
				// if the double on loss option has been enabled
				if (ifdouble == true)
				{
					// if it is not the first loss in the loss sequence
					if (firstOriginalBet == false)
					{
						bet = parseInt(originalBet,10);						// set the bet to the value of the original bet
						document.getElementById('bet').value = bet;			// set the bet display to the value of the current bet (original bet)
						firstOriginalBet = true;							// set the first original bet flag to true
					}
				}
				// if the current stake is larger than the current maximum stake
				if (stake > MAXstake)
				{
					MAXstake = parseInt(stake,10);							// set the value of the maximum stake variable to the value of the current stake variable
					document.getElementById('maxstake').value = MAXstake;	// set the value of the maximum stake display to the value of the maximum stake variable
				}
				numRolls = 0;												// reset the number of rolls to 0
			}
			// else the sum of the dice is not equal to 7 or the point
			else
			{
				document.getElementById('winstatus').value = 'Roll again to make ' + point;	// set the win/loss status display to roll again to make the point
				numRolls++;																	// increment the number of rolls
			}
		}
	}
	
	// function to toggle the double on loss flag. when button is clicked, it reverses the flag
	function doubleLosingBet()
	{
		// if the option was enabled when the button was clicked
		if (ifdouble == true)
		{
			ifdouble = false;											// then we now toggle (disable) the option
			document.getElementById('double').value = '';				// the option is disabled, so clear the double on loss display
		}
		// else the option was disabled when the button was clicked
		else
		{
			ifdouble = true;											// the we now toggle (enable) the option
			document.getElementById('double').value = 'Double on loss';	// the option is enabled, so set the double on loss display to "Double on loss"
		}
	}
	
	// function to simulate X number of games, where X represents a number of games that were either won or lost. This automates the game.
	function runSimulation()
	{
		var numGames = prompt('How many games?',1000);		// prompt the user for the number of games to be run in the simulation
		// do not accept a number of games larger than 2000. if the user supplies one larger than 2000, reject it and ask again until 2000 or less is attained
		while (numGames > 2000)
		{
			var numGames = prompt('You entered a number too large.\nHow many games?',1000); // prompt again for number of games
		}
		// note the default for the above is 1000
		var i;						// variable i for the iterating up to numGames
		// for loop from 0 to numGames, there are [numGames] iterations
		for (i = 0; i < numGames;)	
		{
			rollDice();												// call the rollDice function
			var place = document.getElementById('winstatus').value; // get the win/loss status of the game
			// if the user won
			if (place == 'You win!')
			{
				i++;	// increment the number of games played
			}
			// else if the user lost
			else if (place == 'You lose.')
			{
				i++;	// increment the number of games played
			}
		}
	}