code below worked great but when I switch back and forth between car 1 and 2 the value didn't reset.  ok, here the problem...

first select "One A"  from car 1, hit submit, the values show below

Form Fields:
A=1
B=0
then select "One B" from car 2, hit submit, the values show below

Form Fields:
A=1
B=1

 

how can I reset the value of A=0 since the car 1 drop down is not visible at this time.  Or can I just set the attribute for the hidden field to disable so it won't be pass to the next page?

thanks

<script>
$(document).ready(function() {
    $("input[name$='reporttype']").click(function() {
        var type = $(this).val();

        $("div.desc").hide();
        $("#Reporttype" + type).show();
    });
});
 </script>
 
  car 1<input type="radio" name="reporttype" checked="checked" value="1"  />
    car 2: <input type="radio" name="reporttype" value="2" />
   
 <div id="Cars1" class="desc">
       A:  <select name="a" id="com">
            <option value="0" selected="selected">select one</option>
            <option value="1">One A</option>
         </select>
    </div>
    <div id="Cars2" class="desc" style="display: none;">
       B: <select name="com" id="com">
            <option value="0" selected="selected">select one</option>
            <option value="1">One B</option>
         </select>
    </div>

<input type="submit" name="sbumit">