实现页面加载完后触发select的onchange事件

<script>
window.onload = function(){
        var obj = document.getElementById("time_type");
        if(window.event) obj.fireEvent("onchange");
        else{
            var e = document.createEvent(‘HTMLEvents‘);
            e.initEvent("change", false, false);
            obj.dispatchEvent(e);
        }
    }
</script>

    <select id="time_type" name="time_type">
    <option value="1" {if $scheduleItem[‘type‘]==1}selected{/if} >1(每天)</option>
    <option value="2" {if $scheduleItem[‘type‘]==2}selected{/if} >2(每周)</option>
    </select>