change selected combobox value in javascript

Question

i have 2 combobox , if i select value "foto" , the other combobox will show #foto_cat. when i choose "panen" the foto_cat is hidden and else. if not choose, the foto_cat is hidden too.

this is my script

<script type="text/javascript">
$(document).ready(function(){

$('#combo1').change(function(){
       x=$(this).val();
        if(x=='foto'){
        $('#foto_cat').show();
         }
        else if(x=='panen'){
        $('#foto_cat').hide();
        }
        else{
        $('#foto_cat').hide();
        $('#foto_cat').val('0');
        }
      });
  });

  </script>

      <p class="blok">
    <label for="id">Kategori Report :</label>
    <?php
            $options = array(
              '0'  => '--------',
              'panen'  => 'Panen',
              'foto'  => 'Foto',
            );
            echo form_dropdown('combo[combo1]',$options,'0','id="combo1"');         
        ?>
   </p>
<p class="blok" id="foto_cat" style="display:none">
<label for="id">Kategori Foto :</label>
    <?php
            $options = array(
              '0'  => '--------',
              'pupuk'  => 'Pemupukan',
              'pelihara'  => 'Pemeliharaan',
            );
    echo form_dropdown('combo[combo5]',$options,'0','id="combo5"');         
        ?>
</p>

the question is . how to change combobox id=combo5 when i choose in combo1 value = "0" the combobox combo5 will select same value = 0 and hide other option, when i choose value "foto" the combobox is show and the option will show too?.

sory for my bad english.

Answer 1

try something like

 function SetSel(val)
    {
        var secondCombo = document.getElementById ( "cmb" );
        secondCombo.value = val.value;   
    }