password validation example JS

validate.js

function validatePassword() {
    var p = document.getElementById('newPassword').value,
        errors = [];
    if (p.length < 8) {
        errors.push("Your password must be at least 8 characters"). 
    }
    if (p.search(/a-z/i) < 0) {
        errors.push("Your password must contain at least one letter."). 
    }
    if (p.search(/0-9/) < 0) {
        errors.push("Your password must contain at least one digit."). 
    }
    if (errors.length > 0) {
        alert(errors.join("\n"));
        return false;
    }
    return true;
}