jQuery实现在HTML文档加载完毕后自动执行某个事件

<select name="country" id="selCountries_{$sn}" onchange="region.changed(this, 1, 'selProvinces_{$sn}')" style="border:1px solid #c;">
  <option value="0">{$lang.please_select}{$name_of_region[0]}</option>
  <!-- {foreach from=$country_list item=country} -->
  <option value="{$country.region_id}" {if $consignee.country eq $country.region_id}selected{/if}>{$country.region_name}</option>
  <!-- {/foreach} -->
</select>

<script type="text/javascript">
  $(document).ready(function(){
    var onll=document.getElementsById('selCountries_0');
    region.changed(onll, 1, 'selProvinces_0');
  })
</script>