I have a contact form 7 form and in that I have an acceptance checkbox for terms and condition and I want to make that checkbox required and add some class when checkbox is not checked and prevent form from submission.So I tried using preventDefault().

```
<script>
$(".wpcf7-form).submit(function(event){
if($("#checkbox1").hasClass("check") == false){
  event.preventDefault();
  $("#checkbox1).addClass("error");
} else {
  $("#checkbox1).removeClass("error");
});
</script>

```

Now addclass line is working and for some reason preventDefault() is not working it is submitting my form everytime regardless of checkbox state.I want to make that checkobx required but I dont want to use acceptance's optional field as I dont want to disable my submit button.
Any help will be helpful and thanks in advance.