Implement validator

validator.js

@@ -1,7 +1,72 @@
+(function(){
 
-  //insert your code here
-
-$(function(){
+  var inputs = document.getElementsByTagName("input");
+  var errors = document.getElementsByTagName("li");
+  var submitButton = inputs[2];
+  var form = (document.getElementsByTagName("form"))[0];
+  var anyErrors; 
+
+  // initialize: all errors off
+  for (var i = 0; i < errors.length; i++) {
+    errors[i].style.display = "none";
+  }
+
+  // check for errors when submit button is pressed
+  submitButton.addEventListener("click", function() {
+
+    anyErrors = false;
+    var email = inputs[0].value;
+    var password = inputs[1].value;
+
+    emailValidation(email);
+    lengthCheck(password);
+    uppercaseCheck(password);
+    numberCheck(password);
+
+  });
+
+  //stop form submission if there's an error 
+  form.onsubmit = function(){
+    if (anyErrors) {
+      return false;
+    }
+  }
+
+  // email is valid?
+  var emailValidation = function(email) {
+    var emailRegex = /[a-zA-Z0-9.+_\-]+@[a-zA-Z0-9.+_\-]+\.[a-zA-Z]+/;
+    var isError = !(emailRegex.test(email));
+    setError(isError, 0);
+  }
+
+  // password is at least 8 in length?
+  var lengthCheck = function(password) {
+    var isError = (password.length < 8);
+    setError(isError, 1);
+  }
+
+  // password contains an uppercase letter?
+  var uppercaseCheck = function(password) {
+    var isError = (password == password.toLowerCase());
+    setError(isError, 2);
+  }
+
+  // password contains a number?
+  var numberCheck = function(password) {
+    var numberRegex = /\d/
+    var isError = !(numberRegex.test(password));
+    setError(isError, 3);
+  }
+
+  // if there's an error, display appropriate message
+  var setError = function(isError, errorNumber) {
+    if (isError) {
+      errors[errorNumber].style.display = "";
+      anyErrors = true;
+    } else {
+      errors[errorNumber].style.display = "none";
+    }
+  }
+
+})();
 
-  //insert your code here
-});