selectbox
html
<select name="param1" id="select1">
<option value="">---------</option>
</select>
code1:
$('#select1').append($('<option>').attr({ value: value.id }).text(value.label));
code2:
$('#select1 > option').remove();
code3:
var f = function(){ };
$('#select1').change(f).keypress(f);