Here you go, this is working code for you.
var wordsArray = ["monitor", "program", "application", "keyboard", "javascript", "gaming", "network"];
var word;
var goesLeft;
var placeholder;
var input;
var wordLength;
var currentWord;
function newGame(){
placeholder = "";
goesLeft = 10;
word = wordsArray[getRandom(0,wordsArray.length)];
wordLength = word.length;
console.log(word);
var myElement = document.getElementById("button").innerHTML = "Click to guess";
var myPicElement = document.getElementById("hangimage").src = "http://fetlar.kingston.ac.uk/pp/hangman10.jpg";
for (var count = 0; count < word.length; count++)
{
placeholder = placeholder + "-";
}
document.getElementById("placeholder").innerHTML = placeholder;
document.getElementById("gamestatus").innerHTML = "Game running";
}
function getRandom(min,max){
return Math.floor(Math.random() * (max - min) + min);
}
function guessLetter()
{
var correct = 0;
var inputBox = document.getElementById("guessinput");
input = inputBox.value;
for (var count = 0; count < wordLength; count++)
{
if (input == word.substring(count, count + 1))
{
correct++;
placeholder = placeholder.substring(0, count) + input + placeholder.substring(count + 1, placeholder.length + 1);
document.getElementById("placeholder").innerHTML = placeholder;
}
}
if (correct == 0)
{
goesLeft--;
}
var url = document.getElementById("hangimage").src = "http://fetlar.kingston.ac.uk/pp/hangman" + goesLeft + ".jpg";
if (placeholder == word)
{
document.getElementById("hangimage").src = "http://fetlar.kingston.ac.uk/pp/hangman_win.jpg";
alert("You guessed the word correctly. You win!");
}
if (goesLeft == 0)
{
alert("You lose");
newGame();
}
}
newGame();
document.getElementById("button").onclick = guessLetter;
I suggest you should make a class for this, it will be better.