https://www.four.co.uk/wp-content/plugins/simple-constant-contact/js/simpleCC.js?ver=7.0.5

1function simpleCC_message()
2{
3    // save values from form for error checking
4    var firstName = document.forms["simpleCC_form"]["simpleCC_fname"].value;
5    var lastName = document.forms["simpleCC_form"]["simpleCC_lname"].value;
6    var email = document.forms["simpleCC_form"]["simpleCC_email"].value;
7
8    // test for null or empty values
9    if (firstName==null || firstName=="", lastName==null || lastName=="", email==null || email=="")
10    {
11      document.getElementById('simpleCC_error_message').innerHTML = 'Please fill in all fields';
12      return false;
13    }
14    else
15    {
16        // clear any errors set success to true and submit form
17        document.getElementById('simpleCC_error_message').innerHTML = '';
18        document.forms["simpleCC_form"]["simpleCC_submitted"].value = 'success';
19        document.forms["simpleCC_form"].submit();
20    }
21}