Jquery Breaking out of IF Statement - EXIT;

I've got a statement like this :

$("#submit").click(function(e) {
        if (!confirm('Continue ?')) { return false; }


            if (!$("#all").is(':checked')) {
                $(".A").each(function() {
                    if($(this).val() == '0') { alert ('A - This Value Must Be Set'); return false; }
                });

                $(".B").each(function() {
                    if($(this).val() == '0') { alert ('B - This Value Must Also Be Set'); return false; }
                });

                $(".C").each(function() {
                    if ($(this).val().length < 1) { alert ('C - This Must Be Set'); return false; } 
                    if (!$.isNumeric(this.value)) { alert ('C - Only Numeric Values'); return false; }
                });
            }
    });

If any class 'A' has the value of 0 then I get an alert:

A - This Value Must Be Set

This is fine, but I then get checked by the class 'B' & class 'C' check. What I want it to do is stop all extra checking when either an A, B & C Alert are sent.

Can that be done ?

Thanks