In HTML$/$ JS$,$ how do you stop multiple guesses of the same letter? Stop$/$disable the guesses button, and have a dialog$/$ pop$-$up for losing and winning $($it Should be in the updatePage$()).$ ;$)...$

var POSSIBLE$\_$WORDS $=["$obdurate$",$ "verisimilitude", "defenestrate", "obsequious", "dissonant", "toady", "idempotent"$]$;

var word $=""$;

var guesses $=""$;

var MAX$\_$GUESSES $=6$;

var guessCount;

function newGame$()\{$

guessCount $=$ MAX$\_$GUESSES;

guesses $=""$;

var randomIndex $=$ parseInt$($Math$.$random$()*$ POSSIBLE$\_$WORDS.length$)$;

word $=$ POSSIBLE$\_$WORDS$[$randomIndex$]$;

updatePage$()$;

$\}$

function updatePage$()\{$

$//$update the clueString

var clueString $=""$; $//$This will be the var that holds the current $\_$ or letters

for $($var i $=0$; i $$ word.length; i$++)\{$

var currentLetter $=$ word$[$i$]$;

if $($guesses$.$indexOf$($currentLetter$)>=0)\{$

clueString $+=$ currentLetter $+""$

$\}$

else $\{$

clueString $+="\_"$;

$\}$

$\}$

var clue $=$ document.getElementById$("$clue$")$;

clue.innerHTML $=$ clueString;

$//$update the bank

var guessArea $=$ document.getElementById$("$guesses$")$;

guessArea.innerHTML $=$ guesses

guessBox.value $=""$;

$//$update the picture

var image $=$ document.getElementById$("$hangmanpic$")$;

image.src $=$ "img$/$hangman$"+$ guessCount $+".$gif";

$\}$

function guessLetter$()\{$

var input $=$ document.getElementById$("$guess$")$;

var letter $=$ input.value;

if $($word$.$indexOf$($letter$)<mtext></mtext><mn>0</mn><mi>)</mi><mtext></mtext><mi>\{</mi>$

guessCount$--$;

$\}$

input.value $=""$;$//$emtpy box

guesses $+=$ letter;

updatePage$()$;

$\}$