获取select的值

页面：

 <tr>
<td>报表类型：</td>
<td>
<select id="reporttimetype" name="reporttimetype">

<%
HashMap map = ReportConstants.getReportTypeDic(index_label,orgtype);
Iterator iter = map.keySet().iterator();
while(iter.hasNext()){
String key = (String) iter.next();
String value = (String)map.get(key);
%>
<option value="<%=key %>"><%=value %></option>
<%
}
%>
</select>
</td>
</tr>

方法：

document.getElementById("reporttimetype").onchange=_f;
function _f(){
var options=$("#reporttimetype option:selected");  //获取选中的项
if(options.val()=="2"){
$("#msgweekTr").css("display","inline");
$("#msgdayTr").css("display","none");
}else if(options.val()=="1"){
$("#msgdayTr").css("display","inline");
$("#msgweekTr").css("display","none");
}
}