function getPrefsOption(target_id,obj_select,defs){
if( !defs ) defs='blank';
var selected_value;
for(i = 0; i < obj_select.length ; i++){
	if( obj_select.options[i].selected ){
		selected_value = obj_select.options[i].value;
	}
}
	$.ajax({
	   type: "GET",
	   url: "/special/mytown/js/get_city_list.php" + "?" + "jis_2=" + selected_value + "&def_type=" + defs,
	   success: function(msg){
           $('#'+target_id).html(msg);
	   }
	 });
	
}