<select name="limit" onchange="selectStages()"> //绑定onchange事件
                	<option>请选择期限</option>
                	{loop $limit $item}
                		<option value="{$item}">{$item}</option>
                	{/loop}
</select>
function selectStages(){
	var selectNodesObj = document.getElementById('qx');
	var selIndex = selectNodesObj.selectedIndex;	 //获取当前选择的选项的index值
	var selValue = selectNodesObj.options[selIndex].value; //获取当前选择项的值