javascript 获取 sx:datetimepicker 的值

<div align="center"><sx:datetimepicker label="Start_Time" id="Start_Time" name="Start_Time1"
displayFormat="yyyy/MM/dd" /></div>
<div align="center"><sx:datetimepicker label="End_Time" name="End_Time" displayFormat="yyyy/MM/dd"/></div>
<input id="test" type="text" >
<script language="Javascript">
function myFunction(){
alert("begin");
var testdate= dojo.widget.byId("Start_Time");
alert(testdate.getValue());
return
false;
}
</script>
<s:submit value="Add" onclick="return myFunction();"/>
</div>

巴特西