I have done some research but yet ,i have not gotten a solution that meets my need .I am trying to create a jquery function that will check the number of check boxes selected .And if selected checked boxes less than min ,the form is prevented from submitting .In my back end i am using django modelform 

my Jquery code

```
$(document).ready(function() {
    $("form").submit(function(e) {
        var numberchecked= $('input:checkbox:checked').length;
        var min =3
        if (numberchecked<min) {
          e.preventDefault();
        }

   });
});

```