diff --git a/script.js b/script.js
index 3df1217..7dcd791 100644
--- a/script.js
+++ b/script.js
@@ -1,6 +1,120 @@
-console.log("hello script js");
 
-var inputHappened = function(currentInput){
-  console.log( currentInput );
-  return "WOW SOMETHING HAPPEND";
+let secretWordsStr = "cat,doggy,alphabet";
+let secretWordsArr = secretWordsStr.split(',');
+let SECRET_WORDS = secretWordsArr.map(word => word.split(''));
+
+let tableFlipCharacters = "(╯ರ ~ ರ）╯︵ ┻━┻".split(' ');
+let numGuessChancesLeft = tableFlipCharacters.length;
+let correctGuesses = [];
+let flippedCharacters = [];
+let gameBoard = [];
+let gameBoardStr = "";
+
+String.prototype.replaceAt=function(index, replacement) {
+  return this.substr(-1, index) + replacement+ this.substr(index + replacement.length);
+};
+const sanitizeInput = input => input.trim();
+const isGameOver = lifePoints => lifePoints === 0;
+const isUserWon = (guessedWords, secretWords) => correctGuesses.length === secretWords.flat()
+  .reduce((totalLength, word) => totalLength = totalLength + word.length, 0);
+const getCurrentGuessChar = userGuess => userGuess.charAt(userGuess.length - 1);
+const madeCorrectGuess = (userGuess, secretWords) => secretWords.some(word => word.includes(userGuess));
+/* === long version ===
+* function makeCorrectGuess (userGuess, secretWords) {
+*   for (let i = 0; i < secretWords.length; i++ ) {
+*     let word = secretWords[i]
+*     for (let j = 0; j <  word.length; j++) {
+*       let letter = word[j];
+*       if (userGuess === letter) return true
+*     }
+*   }
+* */
+const isWrongGuess = (userGuess, secretWords) => !madeCorrectGuess(userGuess, secretWords);
+// displays letter place holders at start of game
+const formatGameBoard = gameBoard => gameBoard.join("<br>");
+const replaceBrByNewLine = gameBoardStr => gameBoardStr.replace(/<br>/g,"\n");
+const initGameBoard = secretWordsArr => {
+  gameBoard = secretWordsArr.map(word => "_".repeat(word.length) );
+  gameBoardStr = formatGameBoard(gameBoard);
+  document.querySelector('#output').innerHTML= gameBoardStr;
+};
+const isAdminMode = input => input === "admin";
+const isEndAdminMode = input=> input === "endadmin";
+
+const updateOutput = (outputStr => document.getElementById('output').textContent = outputStr);
+const resetInputBox = () => document.getElementById('input').value="";
+
+/* update gamebaord to replace correct guesses with the right letter */
+const updateGameBoard = userGuess => {
+  let wordIndex = null;
+  let letterIndex = null;
+
+  for (let i = 0; i < secretWordsArr.length; i++) {
+    let word = secretWordsArr[i];
+    if (word.indexOf(userGuess)!==-1) {
+      wordIndex = i;
+      letterIndex = word.indexOf(userGuess) ;
+    }
+  }
+  if (wordIndex!==null && letterIndex !== null) {
+    gameBoard[wordIndex][letterIndex] = userGuess;
+  }
+
+  let pieceToReplace = gameBoard[wordIndex];
+  gameBoard[wordIndex] = pieceToReplace.replaceAt(letterIndex, userGuess);
+  gameBoardStr = formatGameBoard(gameBoard);
+  gameBoardStr = replaceBrByNewLine(gameBoardStr);
+};
+
+
+initGameBoard(secretWordsArr);
+
+const updateSecretWords= userInput => {
+  secretWordsArr.concat(',', userInput);
+  secretWordsArr = secretWordsStr.split(',');
+  SECRET_WORDS = secretWordsArr.map(word => word.split(''));
 };
+
+const inputHappened = function (currentInput) {
+  // assumptions:
+  // - user types one letter at a time | guess character is always last letter of input
+  // - user does not press backspace key to delete a typed character
+  // - letters in secret word do not repeat
+  let userInput = sanitizeInput(currentInput);
+
+  if (isAdminMode(userInput)) {
+    while(!isEndAdminMode(userInput)) {
+      updateSecretWords(userInput);
+      userInput = "";
+      updateOutput(`Admin Mode:\\n
+            Your current secret words: ${secretWordsArr}\\n
+            You have added new word: ${userInput}\\n\``);
+      resetInputBox();
+    }
+  }else {
+    return `Admin Mode:\n
+            Your current secret words: ${secretWordsArr}\n
+            You have added new word: ${userInput}\n`;
+  }
+
+  let userGuess = getCurrentGuessChar(userInput);
+  if (isGameOver(numGuessChancesLeft)) return "Game Over!\n" + gameBoardStr;
+  if (isUserWon(correctGuesses, SECRET_WORDS)) return "You Won!\n" + gameBoardStr;
+
+  if (madeCorrectGuess(userGuess, SECRET_WORDS)) {
+    correctGuesses.push(userGuess);
+    updateGameBoard(userGuess);
+    return `You made a correct guess\n ${flippedCharacters.join('')} \n ${gameBoardStr}`;
+  }
+
+  if (isWrongGuess(userGuess, SECRET_WORDS)) {
+    flippedCharacters.push(tableFlipCharacters.pop());
+    numGuessChancesLeft--;
+    updateGameBoard(userGuess);
+    return `You made a wrong guess. \n ${flippedCharacters.join('')} \n ${gameBoardStr}`;
+  }
+};
+
+
+
+