diff --git a/index.js b/index.js
index 5c705b5..92c0e19 100644
--- a/index.js
+++ b/index.js
@@ -2,11 +2,25 @@ $(document).ready(function() {
   // when the document is ready, set up an input event listener
   $('#first-name, #last-name').on('input', function() {
     // get the current value of the first and last name fields
-    var firstName = $('#first-name').val();
-    var lastName = $('#last-name').val();
-    // concatenate the first and last name values to create a full name
-    var fullName = firstName + ' ' + lastName;
-    // set the concatenated value in full name
-    $('#full-name').val(fullName);
+    var firstName = $('#first-name').val().trim();
+    var lastName = $('#last-name').val().trim();
+    // check if the first and last name fields only contain alphabets using a regular expression
+    var nameRegex = /^[a-zA-Z]+$/;
+    if (firstName !== '' && lastName !== '' && nameRegex.test(firstName) && nameRegex.test(lastName)) {
+      // concatenate the first and last name values to create a full name
+      var fullName = firstName + ' ' + lastName;
+      // set the concatenated value in full name
+      $('#full-name').val(fullName);
+      // clear any error messages
+      $('#error-message').text('');
+    } else {
+      // if either field contains non-alphabetic characters, clear the full name and show an error message
+      $('#full-name').val('');
+      if (firstName !== '' && lastName !== '') {
+        $('#error-message').text('Please enter valid first name and last name');
+      } else {
+        $('#error-message').text('');
+      }
+    }
   });
 });
diff --git a/index.php b/index.php
index 8389980..d8f06dd 100644
--- a/index.php
+++ b/index.php
@@ -23,6 +23,9 @@
       <br>
       <button type="submit">Submit</button>
     </form>
+    <!-- create a div to display error messages -->
+    <div id="error-message"></div>
+
     <?php
     // include logic.php to handle form submission 
     include 'logic.php';