Chile.html

<h1>Vote for your favorit chile</h1>

<input type="button" 
        value="Red Chile" 
        style="background-color: red"
        onclick="makePageRed()" >
<input type="button" 
        value="Green Chile" 
        style="background-color: green"
        onclick="makePageGreen()" >
<br>
<input type="text" id="FullName" >
<input type="button"
        value="Is Letter Y?"
        onclick="isLetterY()" >
<br>
<input type="number" id="FirstNumber">
 + 
<input type="number" id="SecondNumber">
 = 
<input type="button" value="Go" onclick="AddEm()">
<div id="Answer">...</div>

<script>
    function AddEm() {
        var firstNumber = document.getElementById("FirstNumber").value;
        var secondNumber = document.getElementById("SecondNumber").value;
        var answer = document.getElementById("Answer");

        var theSum = Number(firstNumber) + Number(secondNumber);
        answer.innerHTML = theSum.toString();
    }

    function isLetterY() {
        var fullName = document.getElementById("FullName").value;

        if (fullName.length < 4) {
            alert("Please type in a name first!");
            return;
        }

        for (var counter = 0; counter < fullName.length; counter++) {
            var currentLetter = fullName.substr(counter, 1);
            if (currentLetter === "Y") {
                console.log("Yes");
            } else {
                console.log("No");
            }
        }
    }

    var counter = 0;

    function makePageRed() {
        counter = counter + 1;
        if (counter > 2) {
            document.body.style.backgroundColor = "red";
            counter = 0;
        } else {
            document.body.style.backgroundColor = "white";
        }
    }

    function makePageGreen() {
        document.body.style.backgroundColor = "green";

        for (var i = 0; i < 10; i++) {
            console.log(i);
        }
    }
</script>