Adding a submit button to explicitly trigger parsing instead of occurring on change of the input box.

Author: wimpyprogrammer

index.html

@@ -59,7 +59,12 @@
 			<div class="container">
 				<form class="form-horizontal js-input-form">
 					<label for="input">Expression to parse</label>
-					<textarea class="form-control js-tutorial-input" id="input" placeholder="Enter your expression"></textarea>
+					<div class="input-group">
+						<textarea class="form-control js-tutorial-input" id="input" placeholder="Enter your expression"></textarea>
+						<span class="input-group-btn">
+							<button type="button" class="btn btn-primary btn-lg js-submit">Submit</button>
+						</span>
+					</div>
 				</form>
 			</div>
 		</div>

js/main.js

@@ -131,14 +131,15 @@ define(function(require, exports, module) {
 
   $(function() {
     var $input = $('#input'),
+        $submit = $('.js-submit'),
         $inputForm = $('.js-input-form'),
         $introText = $('.js-intro-text'),
         $alertMixedOperators = $('.js-alert-mixed-operators'),
         $truthTable = $('.js-truth-table'),
         $startTutorial = $('.js-tutorial-start'),
         lastTutorialStepNum = null;
 
-    $input.change(function() {
+    $submit.on('click keypress', function() {
       var input = $input.val(),
           expression, columnClasses;