diff --git a/public/index.html b/public/index.html
index 995fcd4..92d6d52 100644
--- a/public/index.html
+++ b/public/index.html
@@ -135,7 +135,7 @@ <h4 class="center-align">How To Use</h4>
             <div class="col l4 s12 m12 push-l7">
               <div id="result-area" class="row">
                 <h5 class="center-align">Result</h5>
-                <p class="error center-align">{{error}}</p>
+                <!--<p class="error center-align">{{error}}</p>-->
                 <div id="result" class="center-align">
                   {{result}}
                 </div>
@@ -144,20 +144,20 @@ <h5 class="center-align">Result</h5>
             <div class="col l5 s12 m12 pull-l3">
               <div class="row">
                 <div class="input-field col l12">
-                  <input placeholder="Enter text to test" id="input" type="text" class="validate" ng-model="input">
+                  <input placeholder="Enter text to test" id="input" type="text" class="validate" ng-model="input" ng-change="{{ selected !== '' ? getResult() : '' }}">
                   <label for="input">String Input</label>
                 </div>
                 <div class="input-field col l12">
-                  <select ng-model="selected">
+                  <select ng-model="selected" ng-selected="{{ input !== '' ? getResult() : ''}}">
                     <option value="" disabled selected>Choose your option</option>
                     <option ng-repeat="option in options" ng-model="selected" value="{{option}}">{{option}}</option>
                   </select>
                   <label>Methods</label>
                 </div>  
               </div>
-              <div class="row">
+              <!--<div class="row">
                 <button class="waves-effect waves-light green btn" ng-click="getResult(input, selected)">Get Result</button>
-              </div>
+              </div>-->
             </div>
           </div>
         </div>
diff --git a/public/js/app.js b/public/js/app.js
index c816917..54821dd 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -18,21 +18,13 @@ angular.module('StringExtension', [])
     'isDigit',
     'doubleCheck'
   ];
-
   $scope.result = '';
-  $scope.error = '';
-  $scope.getResult = (input, selected) => {
-    if (input === '' || input === undefined) {
-      $scope.result = '';
-      $scope.error = 'You did not enter any text';
-      return;
-    } else if (selected === undefined) {
-      $scope.result = '';
-      $scope.error = 'You did not select a method';
-      return;
+  $scope.getResult = () => {
+    try {
+      $scope.input && $scope.selected ? ($scope.result =  $scope.input[$scope.selected]()) : '';
+    } catch (error) {
+      $scope.result = error.message;
     }
-    $scope.error = '';
-    $scope.result = input[selected]();
-    return;
+    return $scope.result;
   }
 }])
\ No newline at end of file
diff --git a/src/string.js b/src/string.js
index 1dd5211..28212f0 100644
--- a/src/string.js
+++ b/src/string.js
@@ -48,8 +48,8 @@ const stringClassExtensions = {
    * @returns {Boolean} true or false
    */
   isQuestion() {
-    const regexType = /\?$/g;
-    return regexType.test(this);
+    const regexType = /^[\w]+([. \w]+)?\?$/;
+    return regexType.test(this.trim());
   },
 
   /**
@@ -76,17 +76,12 @@ const stringClassExtensions = {
    * @returns {String} string of numbers
    */
   toCurrency() {
-    if (!Number(this)) {
-      return 'This is not a Number';
+    if (/[^\d.]/.test(this) || /\..*\./.test(this)) {
+      throw new TypeError('Invalid number');
     }
-    let [number, decimal] = this.split(/\./g);
-    if (decimal === undefined) {
-      decimal = '00';
-    } else {
-      decimal = decimal.substring(0, 2);
-    }
-    number = number.replace(/(\d)(?=(\d{3})+(?!\d))/g, '$1,');
-    return `${number}.${decimal}`;
+
+    const currencyValue = Number(this).toFixed(2);
+    return currencyValue.replace(/(\d)(?=(\d{3})+(?!\d))/g, '$1,');
   },
 
   /**
diff --git a/test/string.test.js b/test/string.test.js
index ccd8d45..8f1df5e 100644
--- a/test/string.test.js
+++ b/test/string.test.js
@@ -1,6 +1,9 @@
+/* eslint amd:true */
 /* eslint no-unused-expressions: 0 */
-const mocha = require('mocha');
-const expect = require('chai').expect;
+const chai = require('chai');
+
+const expect = chai.expect;
+const assert = chai.assert;
 
 require('../src/string');
 
@@ -76,18 +79,18 @@ describe('String Class', () => {
     it('returns a currency representation of the String', () => {
       expect('11111.11'.toCurrency()).to.equal('11,111.11');
       expect('2535678'.toCurrency()).to.equal('2,535,678.00');
+      expect('1234567.'.toCurrency()).to.equal('1,234,567.00');
     });
-    it('returns an error message if the string is not of a "number"', () => {
-      expect('Mother'.toCurrency()).to.deep.equal('This is not a Number');
-      expect('Andela'.toCurrency()).to.deep.equal('This is not a Number');
+    it('should throw an error for invalid numbers', () => {
+      assert.throws('Mother'.toCurrency, TypeError, 'Invalid number');
+      assert.throws('15248.15.45'.toCurrency, TypeError, 'Invalid number');
     });
   });
 
   describe('fromCurrency', () => {
     it('returns a number representation of the currency string', () => {
-      expect('11,111.11'.fromCurrency()).to.equal('11111.11');
-      expect('2,535,678.00'.fromCurrency()).to.equal('2535678.00');
       expect('2,535,678'.fromCurrency()).to.equal('2535678');
+      expect('2,535,678.11'.fromCurrency()).to.equal('2535678.11');
     });
   });