script.js

// Example One
function validateForm() {
    let x = document.forms["myForm"]["fname"].value;
    if (x == "") {
        alert("Name must be filled out");
        return false;
    }
}


//Example Two
let textOne = document.getElementById('textOne');

function FunctionOne() {
    // Get the value of the input field with id="numb"
    let x = document.getElementById("numb").value;
    // If x is Not a Number or less than one or greater than 10
    let text;
    if (isNaN(x) || x < 1 || x > 10) {
        text = "Input not valid";
    } else {
        text = "Input OK";
    }
    textOne.innerHTML = text;
}