<select id="selectId">
<option value="a">选项一</a>
<option value="b">选项二</a>
<option value="b">选项三</a>
</select>
<script type="text/JavaScript">
var selectId = document.getElementById("selectId");//获取ID
selectId.onchange = function()//触发事件
{
var result = selectId.options[selectId.selectedIndex].innerHTML;//获取选中文本
alert(result);
}
</script>